Method and apparatus for event-based uplink transmit beam switch

ABSTRACT

A method for operating a user equipment comprises receiving configuration information including information on a beam indication indicating N uplink (UL) transmit beams, where N&gt;1; receiving the beam indication; determining whether an event is detected; selecting a beam from the N UL transmit beams based on whether the event is detected or not; and transmitting an UL transmission using the selected beam, wherein the beam refers to a spatial property used to receive or transmit a source reference signal (RS).

CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM OF PRIORITY

The present application claims priority to U.S. Provisional PatentApplication No. 63/044,838, filed on Jun. 26, 2020, and U.S. ProvisionalPatent Application No. 63/052,830, filed on Jul. 16, 2020. The contentof the above-identified patent documents is incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates generally to wireless communicationsystems and more specifically to event-based uplink transmit beamswitching.

BACKGROUND

Understanding and correctly estimating the channel between a userequipment (UE) and a gNode B (gNB) is important for efficient andeffective wireless communication. In order to correctly estimate thedownlink (DL) channel conditions, the gNB may transmit a referencesignal, e.g., CSI-RS, to the UE for DL channel measurement, and the UEmay report (e.g., feedback) information about channel measurement, e.g.,CSI, to the gNB. Likewise, for uplink (UL), the UE may transmitreference signal, e.g., SRS, to the gNB for UL channel measurement. Withthe DL and UL channel measurements, the gNB is able to selectappropriate communication parameters to efficiently and effectivelyperform wireless data communication with the UE. For a millimeter wavecommunication systems, the reference signal can correspond to a spatialbeam, and the CSI can correspond to a beam report which indicates apreferred spatial beam for communication. In such beamformed systems, abeam indication mechanism is needed in order to align the spatial beamsat both gNB and UE.

SUMMARY

Embodiments of the present disclosure provide methods and apparatuses toenable event-based uplink transmit beam switching.

In one embodiment, a UE in a wireless communication system is provided.The UE includes a transceiver configured to: receive configurationinformation including information on a beam indication indicating Nuplink (UL) transmit beams, where N>1, and receive the beam indication.The UE further includes a processor operably coupled to the transceiver.The processor is configured to: determine whether an event is detected,and select a beam from the N UL transmit beams based on whether theevent is detected or not. The transceiver is further configured totransmit an UL transmission using the selected beam, and the beam refersto a spatial property used to receive or transmit a source referencesignal (RS).

In another embodiment, a BS in a wireless communication system isprovided. The BS includes a processor configured to generateconfiguration information including information on a beam indicationindicating N uplink (UL) transmit beams, where N>1, and generate thebeam indication. The BS further includes a transceiver operably coupledto the processor. The transceiver is configured to: transmit theconfiguration information, transmit the beam indication, and receive anUL transmission transmitted using a beam from the N UL transmit beams,wherein the beam is selected based on whether an event is detected, andwherein the beam refers to a spatial property used to receive ortransmit a source reference signal (RS).

In yet another embodiment, a method for operating a UE is provided. Themethod comprises: receiving configuration information includinginformation on a beam indication indicating N uplink (UL) transmitbeams, where N>1; receiving the beam indication; determining whether anevent is detected; selecting a beam from the N UL transmit beams basedon whether the event is detected or not; and transmitting an ULtransmission using the selected beam, wherein the beam refers to aspatial property used to receive or transmit a source reference signal(RS).

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The term “couple” and its derivativesrefer to any direct or indirect communication between two or moreelements, whether or not those elements are in physical contact with oneanother. The terms “transmit,” “receive,” and “communicate,” as well asderivatives thereof, encompass both direct and indirect communication.The terms “include” and “comprise,” as well as derivatives thereof, meaninclusion without limitation. The term “or” is inclusive, meaningand/or. The phrase “associated with,” as well as derivatives thereof,means to include, be included within, interconnect with, contain, becontained within, connect to or with, couple to or with, be communicablewith, cooperate with, interleave, juxtapose, be proximate to, be boundto or with, have, have a property of, have a relationship to or with, orthe like. The term “controller” means any device, system, or partthereof that controls at least one operation. Such a controller may beimplemented in hardware or a combination of hardware and software and/orfirmware. The functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely. Thephrase “at least one of,” when used with a list of items, means thatdifferent combinations of one or more of the listed items may be used,and only one item in the list may be needed. For example, “at least oneof: A, B, and C” includes any of the following combinations: A, B, C, Aand B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughoutthis patent document. Those of ordinary skill in the art shouldunderstand that in many if not most instances, such definitions apply toprior as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates an example wireless network according to embodimentsof the present disclosure;

FIG. 2 illustrates an example gNB according to embodiments of thepresent disclosure;

FIG. 3 illustrates an example UE according to embodiments of the presentdisclosure;

FIG. 4A illustrates a high-level diagram of an orthogonal frequencydivision multiple access transmit path according to embodiments of thepresent disclosure;

FIG. 4B illustrates a high-level diagram of an orthogonal frequencydivision multiple access receive path according to embodiments of thepresent disclosure;

FIG. 5 illustrates a transmitter block diagram for a PDSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 6 illustrates a receiver block diagram for a PDSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 7 illustrates a transmitter block diagram for a PUSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 8 illustrates a receiver block diagram for a PUSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 9 illustrates an example multiplexing of two slices according toembodiments of the present disclosure;

FIG. 10 illustrates an uplink multi-beam operation according toembodiments of the present disclosure;

FIG. 11 illustrates an uplink multi-beam operation according toembodiments of the present disclosure;

FIG. 12 illustrates a downlink multi-beam operation according toembodiments of the present disclosure;

FIG. 13 illustrates a flow diagram of a UE configured to receive an ULTX beam indication indicating two beams (B₁, B₂) according toembodiments of the present disclosure;

FIG. 14 illustrates a flow diagram of a UE configured to receive an ULTX beam indication indicating two beams (B₁, B₂) according toembodiments of the present disclosure;

FIG. 15 illustrates a flow diagram of a UE configured to receive an ULTX beam indication indicating N beams (B₁, B₂, . . . , B_(N)) accordingto embodiments of the present disclosure;

FIG. 16 illustrates a flow diagram of a UE configured to receive an ULTX beam indication indicating N beams (B₁, B₂, . . . , B_(N)) accordingto embodiments of the present disclosure;

FIG. 17 illustrates an algorithmic description of the UL TX beamselection for UL transmission according to embodiments of the presentdisclosure;

FIG. 18 illustrates a flow chart of a method for operating a UEaccording to embodiments of the present disclosure; and

FIG. 19 illustrates a flow chart of a method for operating a BSaccording to embodiments of the present disclosure.

DETAILED DESCRIPTION

FIG. 1 through FIG. 19, discussed below, and the various embodimentsused to describe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any suitably arranged system or device.

The following documents and standards descriptions are herebyincorporated by reference into the present disclosure as if fully setforth herein: 3GPP TS 36.211 v16.5.0, “E-UTRA, Physical channels andmodulation” (herein “REF 1”); 3GPP TS 36.212 v16.5.0, “E-UTRA,Multiplexing and Channel coding” (herein “REF 2”); 3GPP TS 36.213v16.5.0, “E-UTRA, Physical Layer Procedures” (herein “REF 3”); 3GPP TS36.321 v16.4.0, “E-UTRA, Medium Access Control (MAC) protocolspecification” (herein “REF 4”); 3GPP TS 36.331 v16.4.0, “E-UTRA, RadioResource Control (RRC) protocol specification” (herein “REF 5”); 3GPP TS38.211 v16.5.0, “NR, Physical channels and modulation” (herein “REF 6”);3GPP TS 38.212 v16.5.0, “NR, Multiplexing and Channel coding” (herein“REF 7”); 3GPP TS 38.213 v16.4.0, “NR, Physical Layer Procedures forControl” (herein “REF 8”); 3GPP TS 38.214 v16.4.0, “NR, Physical LayerProcedures for Data” (herein “REF 9”); 3GPP TS 38.215 v16.4.0, “NR,Physical Layer Measurements” (herein “REF 10”); 3GPP TS 38.321 v16.4.0,“NR, Medium Access Control (MAC) protocol specification” (herein “REF11”); and 3GPP TS 38.331 v16.4.1, “NR, Radio Resource Control (RRC)Protocol Specification” (herein “REF 12”).

Aspects, features, and advantages of the disclosure are readily apparentfrom the following detailed description, simply by illustrating a numberof particular embodiments and implementations, including the best modecontemplated for carrying out the disclosure. The disclosure is alsocapable of other and different embodiments, and its several details canbe modified in various obvious respects, all without departing from thespirit and scope of the disclosure. Accordingly, the drawings anddescription are to be regarded as illustrative in nature, and not asrestrictive. The disclosure is illustrated by way of example, and not byway of limitation, in the figures of the accompanying drawings.

In the following, for brevity, both FDD and TDD are considered as theduplex method for both DL and UL signaling.

Although exemplary descriptions and embodiments to follow assumeorthogonal frequency division multiplexing (OFDM) or orthogonalfrequency division multiple access (OFDMA), the present disclosure canbe extended to other OFDM-based transmission waveforms or multipleaccess schemes such as filtered OFDM (F-OFDM).

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems and to enable various verticalapplications, 5G/NR communication systems have been developed and arecurrently being deployed. The 5G/NR communication system is consideredto be implemented in higher frequency (mmWave) bands, e.g., 28 GHz or 60GHz bands, so as to accomplish higher data rates or in lower frequencybands, such as 6 GHz, to enable robust coverage and mobility support. Todecrease propagation loss of the radio waves and increase thetransmission distance, the beamforming, massive multiple-inputmultiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are discussed in5G/NR communication systems.

In addition, in 5G/NR communication systems, development for systemnetwork improvement is under way based on advanced small cells, cloudradio access networks (RANs), ultra-dense networks, device-to-device(D2D) communication, wireless backhaul, moving network, cooperativecommunication, coordinated multi-points (CoMP), reception-endinterference cancellation and the like.

The discussion of 5G systems and frequency bands associated therewith isfor reference as certain embodiments of the present disclosure may beimplemented in 5G systems. However, the present disclosure is notlimited to 5G systems or the frequency bands associated therewith, andembodiments of the present disclosure may be utilized in connection withany frequency band. For example, aspects of the present disclosure mayalso be applied to deployment of 5G communication systems, 6G or evenlater releases which may use terahertz (THz) bands.

FIGS. 1-4B below describe various embodiments implemented in wirelesscommunications systems and with the use of orthogonal frequency divisionmultiplexing (OFDM) or orthogonal frequency division multiple access(OFDMA) communication techniques. The descriptions of FIGS. 1-3 are notmeant to imply physical or architectural limitations to the manner inwhich different embodiments may be implemented. Different embodiments ofthe present disclosure may be implemented in any suitably-arrangedcommunications system. The present disclosure covers several componentswhich can be used in conjunction or in combination with one another orcan operate as standalone schemes.

FIG. 1 illustrates an example wireless network according to embodimentsof the present disclosure. The embodiment of the wireless network shownin FIG. 1 is for illustration only. Other embodiments of the wirelessnetwork 100 could be used without departing from the scope of thisdisclosure.

As shown in FIG. 1, the wireless network includes a gNB 101, a gNB 102,and a gNB 103. The gNB 101 communicates with the gNB 102 and the gNB103. The gNB 101 also communicates with at least one network 130, suchas the Internet, a proprietary Internet Protocol (IP) network, or otherdata network.

The gNB 102 provides wireless broadband access to the network 130 for afirst plurality of user equipments (UEs) within a coverage area 120 ofthe gNB 102. The first plurality of UEs includes a UE 111, which may belocated in a small business; a UE 112, which may be located in anenterprise (E); a UE 113, which may be located in a WiFi hotspot (HS); aUE 114, which may be located in a first residence (R); a UE 115, whichmay be located in a second residence (R); and a UE 116, which may be amobile device (M), such as a cell phone, a wireless laptop, a wirelessPDA, or the like. The gNB 103 provides wireless broadband access to thenetwork 130 for a second plurality of UEs within a coverage area 125 ofthe gNB 103. The second plurality of UEs includes the UE 115 and the UE116. In some embodiments, one or more of the gNBs 101-103 maycommunicate with each other and with the UEs 111-116 using 5G, LTE,LTE-A, WiMAX, WiFi, or other wireless communication techniques.

Depending on the network type, the term “base station” or “BS” can referto any component (or collection of components) configured to providewireless access to a network, such as transmit point (TP),transmit-receive point (TRP), an enhanced base station (eNodeB or eNB),a 5G base station (gNB), a macrocell, a femtocell, a WiFi access point(AP), or other wirelessly enabled devices. Base stations may providewireless access in accordance with one or more wireless communicationprotocols, e.g., 5G 3GPP new radio interface/access (NR), long termevolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA),Wi-Fi 802.11a/b/g/n/ac, etc. For the sake of convenience, the terms “BS”and “TRP” are used interchangeably in this patent document to refer tonetwork infrastructure components that provide wireless access to remoteterminals. Also, depending on the network type, the term “userequipment” or “UE” can refer to any component such as “mobile station,”“subscriber station,” “remote terminal,” “wireless terminal,” “receivepoint,” or “user device.” For the sake of convenience, the terms “userequipment” and “UE” are used in this patent document to refer to remotewireless equipment that wirelessly accesses a BS, whether the UE is amobile device (such as a mobile telephone or smartphone) or is normallyconsidered a stationary device (such as a desktop computer or vendingmachine).

Dotted lines show the approximate extents of the coverage areas 120 and125, which are shown as approximately circular for the purposes ofillustration and explanation only. It should be clearly understood thatthe coverage areas associated with gNBs, such as the coverage areas 120and 125, may have other shapes, including irregular shapes, dependingupon the configuration of the gNBs and variations in the radioenvironment associated with natural and man-made obstructions.

As described in more detail below, one or more of the UEs 111-116include circuitry, programing, or a combination thereof, for receivingconfiguration information including information on a beam indicationindicating N uplink (UL) transmit beams, where N>1; receiving the beamindication; determining whether an event is detected; selecting a beamfrom the N UL transmit beams based on whether the event is detected ornot; and transmitting an UL transmission using the selected beam,wherein the beam refers to a spatial property used to receive ortransmit a source reference signal (RS). One or more of the gNBs 101-103includes circuitry, programing, or a combination thereof, for generatingconfiguration information including information on a beam indicationindicating N uplink (UL) transmit beams, where N>1, generating the beamindication, transmitting the configuration information, transmitting thebeam indication, and receiving an UL transmission transmitted using abeam from the N UL transmit beams, wherein the beam is selected based onwhether an event is detected, and wherein the beam refers to a spatialproperty used to receive or transmit a source reference signal (RS).

Although FIG. 1 illustrates one example of a wireless network, variouschanges may be made to FIG. 1. For example, the wireless network couldinclude any number of gNBs and any number of UEs in any suitablearrangement. Also, the gNB 101 could communicate directly with anynumber of UEs and provide those UEs with wireless broadband access tothe network 130. Similarly, each gNB 102-103 could communicate directlywith the network 130 and provide UEs with direct wireless broadbandaccess to the network 130. Further, the gNBs 101, 102, and/or 103 couldprovide access to other or additional external networks, such asexternal telephone networks or other types of data networks.

FIG. 2 illustrates an example gNB 102 according to embodiments of thepresent disclosure. The embodiment of the gNB 102 illustrated in FIG. 2is for illustration only, and the gNBs 101 and 103 of FIG. 1 could havethe same or similar configuration. However, gNBs come in a wide varietyof configurations, and FIG. 2 does not limit the scope of thisdisclosure to any particular implementation of a gNB.

As shown in FIG. 2, the gNB 102 includes multiple antennas 205 a-205 n,multiple RF transceivers 210 a-210 n, transmit (TX) processing circuitry215, and receive (RX) processing circuitry 220. The gNB 102 alsoincludes a controller/processor 225, a memory 230, and a backhaul ornetwork interface 235.

The RF transceivers 210 a-210 n receive, from the antennas 205 a-205 n,incoming RF signals, such as signals transmitted by UEs in the network100. The RF transceivers 210 a-210 n down-convert the incoming RFsignals to generate IF or baseband signals. The IF or baseband signalsare sent to the RX processing circuitry 220, which generates processedbaseband signals by filtering, decoding, and/or digitizing the basebandor IF signals. The RX processing circuitry 220 transmits the processedbaseband signals to the controller/processor 225 for further processing.

The TX processing circuitry 215 receives analog or digital data (such asvoice data, web data, e-mail, or interactive video game data) from thecontroller/processor 225. The TX processing circuitry 215 encodes,multiplexes, and/or digitizes the outgoing baseband data to generateprocessed baseband or IF signals. The RF transceivers 210 a-210 nreceive the outgoing processed baseband or IF signals from the TXprocessing circuitry 215 and up-converts the baseband or IF signals toRF signals that are transmitted via the antennas 205 a-205 n.

The controller/processor 225 can include one or more processors or otherprocessing devices that control the overall operation of the gNB 102.For example, the controller/processor 225 could control the reception offorward channel signals and the transmission of reverse channel signalsby the RF transceivers 210 a-210 n, the RX processing circuitry 220, andthe TX processing circuitry 215 in accordance with well-knownprinciples. The controller/processor 225 could support additionalfunctions as well, such as more advanced wireless communicationfunctions.

For instance, the controller/processor 225 could support beam forming ordirectional routing operations in which outgoing signals from multipleantennas 205 a-205 n are weighted differently to effectively steer theoutgoing signals in a desired direction. Any of a wide variety of otherfunctions could be supported in the gNB 102 by the controller/processor225.

The controller/processor 225 is also capable of executing programs andother processes resident in the memory 230, such as an OS. Thecontroller/processor 225 can move data into or out of the memory 230 asrequired by an executing process.

The controller/processor 225 is also coupled to the backhaul or networkinterface 235. The backhaul or network interface 235 allows the gNB 102to communicate with other devices or systems over a backhaul connectionor over a network. The interface 235 could support communications overany suitable wired or wireless connection(s). For example, when the gNB102 is implemented as part of a cellular communication system (such asone supporting 5G, LTE, or LTE-A), the interface 235 could allow the gNB102 to communicate with other gNBs over a wired or wireless backhaulconnection. When the gNB 102 is implemented as an access point, theinterface 235 could allow the gNB 102 to communicate over a wired orwireless local area network or over a wired or wireless connection to alarger network (such as the Internet). The interface 235 includes anysuitable structure supporting communications over a wired or wirelessconnection, such as an Ethernet or RF transceiver.

The memory 230 is coupled to the controller/processor 225. Part of thememory 230 could include a RAM, and another part of the memory 230 couldinclude a Flash memory or other ROM.

Although FIG. 2 illustrates one example of gNB 102, various changes maybe made to FIG. 2. For example, the gNB 102 could include any number ofeach component shown in FIG. 2. As a particular example, an access pointcould include a number of interfaces 235, and the controller/processor225 could support routing functions to route data between differentnetwork addresses. As another particular example, while shown asincluding a single instance of TX processing circuitry 215 and a singleinstance of RX processing circuitry 220, the gNB 102 could includemultiple instances of each (such as one per RF transceiver). Also,various components in FIG. 2 could be combined, further subdivided, oromitted and additional components could be added according to particularneeds.

FIG. 3 illustrates an example UE 116 according to embodiments of thepresent disclosure. The embodiment of the UE 116 illustrated in FIG. 3is for illustration only, and the UEs 111-115 of FIG. 1 could have thesame or similar configuration. However, UEs come in a wide variety ofconfigurations, and FIG. 3 does not limit the scope of this disclosureto any particular implementation of a UE.

As shown in FIG. 3, the UE 116 includes an antenna 305, a radiofrequency (RF) transceiver 310, TX processing circuitry 315, amicrophone 320, and receive (RX) processing circuitry 325. The UE 116also includes a speaker 330, a processor 340, an input/output (I/O)interface (IF) 345, a touchscreen 350, a display 355, and a memory 360.The memory 360 includes an operating system (OS) 361 and one or moreapplications 362.

The RF transceiver 310 receives, from the antenna 305, an incoming RFsignal transmitted by a gNB of the network 100. The RF transceiver 310down-converts the incoming RF signal to generate an intermediatefrequency (IF) or baseband signal. The IF or baseband signal is sent tothe RX processing circuitry 325, which generates a processed basebandsignal by filtering, decoding, and/or digitizing the baseband or IFsignal. The RX processing circuitry 325 transmits the processed basebandsignal to the speaker 330 (such as for voice data) or to the processor340 for further processing (such as for web browsing data).

The TX processing circuitry 315 receives analog or digital voice datafrom the microphone 320 or other outgoing baseband data (such as webdata, e-mail, or interactive video game data) from the processor 340.The TX processing circuitry 315 encodes, multiplexes, and/or digitizesthe outgoing baseband data to generate a processed baseband or IFsignal. The RF transceiver 310 receives the outgoing processed basebandor IF signal from the TX processing circuitry 315 and up-converts thebaseband or IF signal to an RF signal that is transmitted via theantenna 305.

The processor 340 can include one or more processors or other processingdevices and execute the OS 361 stored in the memory 360 in order tocontrol the overall operation of the UE 116. For example, the processor340 could control the reception of forward channel signals and thetransmission of reverse channel signals by the RF transceiver 310, theRX processing circuitry 325, and the TX processing circuitry 315 inaccordance with well-known principles. In some embodiments, theprocessor 340 includes at least one microprocessor or microcontroller.

The processor 340 is also capable of executing other processes andprograms resident in the memory 360, such as processes for receivingconfiguration information including information on a beam indicationindicating N uplink (UL) transmit beams, where N>1; receiving the beamindication; determining whether an event is detected; selecting a beamfrom the N UL transmit beams based on whether the event is detected ornot; and transmitting an UL transmission using the selected beam,wherein the beam refers to a spatial property used to receive ortransmit a source reference signal (RS). The processor 340 can move datainto or out of the memory 360 as required by an executing process. Insome embodiments, the processor 340 is configured to execute theapplications 362 based on the OS 361 or in response to signals receivedfrom gNBs or an operator. The processor 340 is also coupled to the I/Ointerface 345, which provides the UE 116 with the ability to connect toother devices, such as laptop computers and handheld computers. The I/Ointerface 345 is the communication path between these accessories andthe processor 340.

The processor 340 is also coupled to the touchscreen 350 and the display355. The operator of the UE 116 can use the touchscreen 350 to enterdata into the UE 116. The display 355 may be a liquid crystal display,light emitting diode display, or other display capable of rendering textand/or at least limited graphics, such as from web sites.

The memory 360 is coupled to the processor 340. Part of the memory 360could include a random access memory (RAM), and another part of thememory 360 could include a Flash memory or other read-only memory (ROM).

Although FIG. 3 illustrates one example of UE 116, various changes maybe made to FIG. 3. For example, various components in FIG. 3 could becombined, further subdivided, or omitted and additional components couldbe added according to particular needs. As a particular example, theprocessor 340 could be divided into multiple processors, such as one ormore central processing units (CPUs) and one or more graphics processingunits (GPUs). Also, while FIG. 3 illustrates the UE 116 configured as amobile telephone or smartphone, UEs could be configured to operate asother types of mobile or stationary devices.

FIG. 4A is a high-level diagram of transmit path circuitry. For example,the transmit path circuitry may be used for an orthogonal frequencydivision multiple access (OFDMA) communication. FIG. 4B is a high-leveldiagram of receive path circuitry. For example, the receive pathcircuitry may be used for an orthogonal frequency division multipleaccess (OFDMA) communication. In FIGS. 4A and 4B, for downlinkcommunication, the transmit path circuitry may be implemented in a basestation (gNB) 102 or a relay station, and the receive path circuitry maybe implemented in a user equipment (e.g., user equipment 116 of FIG. 1).In other examples, for uplink communication, the receive path circuitry450 may be implemented in a base station (e.g., gNB 102 of FIG. 1) or arelay station, and the transmit path circuitry may be implemented in auser equipment (e.g., user equipment 116 of FIG. 1).

Transmit path circuitry comprises channel coding and modulation block405, serial-to-parallel (S-to-P) block 410, Size N Inverse Fast FourierTransform (IFFT) block 415, parallel-to-serial (P-to-S) block 420, addcyclic prefix block 425, and up-converter (UC) 430. Receive pathcircuitry 450 comprises down-converter (DC) 455, remove cyclic prefixblock 460, serial-to-parallel (S-to-P) block 465, Size N Fast FourierTransform (FFT) block 470, parallel-to-serial (P-to-S) block 475, andchannel decoding and demodulation block 480.

At least some of the components in FIGS. 4A 400 and 4B 450 may beimplemented in software, while other components may be implemented byconfigurable hardware or a mixture of software and configurablehardware. In particular, it is noted that the FFT blocks and the IFFTblocks described in this disclosure document may be implemented asconfigurable software algorithms, where the value of Size N may bemodified according to the implementation.

Furthermore, although this disclosure is directed to an embodiment thatimplements the Fast Fourier Transform and the Inverse Fast FourierTransform, this is by way of illustration only and may not be construedto limit the scope of the disclosure. It may be appreciated that in analternate embodiment of the present disclosure, the Fast FourierTransform functions and the Inverse Fast Fourier Transform functions mayeasily be replaced by discrete Fourier transform (DFT) functions andinverse discrete Fourier transform (IDFT) functions, respectively. Itmay be appreciated that for DFT and IDFT functions, the value of the Nvariable may be any integer number (i.e., 1, 4, 3, 4, etc.), while forFFT and IFFT functions, the value of the N variable may be any integernumber that is a power of two (i.e., 1, 2, 4, 8, 16, etc.).

In transmit path circuitry 400, channel coding and modulation block 405receives a set of information bits, applies coding (e.g., LDPC coding)and modulates (e.g., quadrature phase shift keying (QPSK) or quadratureamplitude modulation (QAM)) the input bits to produce a sequence offrequency-domain modulation symbols. Serial-to-parallel block 410converts (i.e., de-multiplexes) the serial modulated symbols to paralleldata to produce N parallel symbol streams where N is the IFFT/FFT sizeused in BS 102 and UE 116. Size N IFFT block 415 then performs an IFFToperation on the N parallel symbol streams to produce time-domain outputsignals. Parallel-to-serial block 420 converts (i.e., multiplexes) theparallel time-domain output symbols from Size N IFFT block 415 toproduce a serial time-domain signal. Add cyclic prefix block 425 theninserts a cyclic prefix to the time-domain signal. Finally, up-converter430 modulates (i.e., up-converts) the output of add cyclic prefix block425 to RF frequency for transmission via a wireless channel. The signalmay also be filtered at baseband before conversion to RF frequency.

The transmitted RF signal arrives at the UE 116 after passing throughthe wireless channel, and reverse operations to those at gNB 102 areperformed. Down-converter 455 down-converts the received signal tobaseband frequency and removes cyclic prefix block 460 and removes thecyclic prefix to produce the serial time-domain baseband signal.Serial-to-parallel block 465 converts the time-domain baseband signal toparallel time-domain signals. Size N FFT block 470 then performs an FFTalgorithm to produce N parallel frequency-domain signals.Parallel-to-serial block 475 converts the parallel frequency-domainsignals to a sequence of modulated data symbols. Channel decoding anddemodulation block 480 demodulates and then decodes the modulatedsymbols to recover the original input data stream.

Each of gNBs 101-103 may implement a transmit path that is analogous totransmitting in the downlink to user equipment 111-116 and may implementa receive path that is analogous to receiving in the uplink from userequipment 111-116. Similarly, each one of user equipment 111-116 mayimplement a transmit path corresponding to the architecture fortransmitting in the uplink to gNBs 101-103 and may implement a receivepath corresponding to the architecture for receiving in the downlinkfrom gNBs 101-103.

A communication system includes a downlink (DL) that conveys signalsfrom transmission points such as base stations (BSs) or NodeBs to userequipments (UEs) and an Uplink (UL) that conveys signals from UEs toreception points such as NodeBs. A UE, also commonly referred to as aterminal or a mobile station, may be fixed or mobile and may be acellular phone, a personal computer device, or an automated device. AneNodeB, which is generally a fixed station, may also be referred to asan access point or other equivalent terminology. For LTE systems, aNodeB is often referred as an eNodeB.

In a communication system, such as LTE system, DL signals can includedata signals conveying information content, control signals conveying DLcontrol information (DCI), and reference signals (RS) that are alsoknown as pilot signals. An eNodeB transmits data information through aphysical DL shared channel (PDSCH). An eNodeB transmits DCI through aphysical DL control channel (PDCCH) or an Enhanced PDCCH (EPDCCH).

An eNodeB transmits acknowledgement information in response to datatransport block (TB) transmission from a UE in a physical hybrid ARQindicator channel (PHICH). An eNodeB transmits one or more of multipletypes of RS including a UE-common RS (CRS), a channel state informationRS (CSI-RS), or a demodulation RS (DMRS). A CRS is transmitted over a DLsystem bandwidth (BW) and can be used by UEs to obtain a channelestimate to demodulate data or control information or to performmeasurements. To reduce CRS overhead, an eNodeB may transmit a CSI-RSwith a smaller density in the time and/or frequency domain than a CRS.DMRS can be transmitted only in the BW of a respective PDSCH or EPDCCHand a UE can use the DMRS to demodulate data or control information in aPDSCH or an EPDCCH, respectively. A transmission time interval for DLchannels is referred to as a subframe and can have, for example,duration of 1 millisecond.

DL signals also include transmission of a logical channel that carriessystem control information. A BCCH is mapped to either a transportchannel referred to as a broadcast channel (BCH) when the DL signalsconvey a master information block (MIB) or to a DL shared channel(DL-SCH) when the DL signals convey a System Information Block (SIB).Most system information is included in different SIBs that aretransmitted using DL-SCH. A presence of system information on a DL-SCHin a subframe can be indicated by a transmission of a correspondingPDCCH conveying a codeword with a cyclic redundancy check (CRC)scrambled with system information RNTI (SI-RNTI). Alternatively,scheduling information for a SIB transmission can be provided in anearlier SIB and scheduling information for the first SIB (SIB-1) can beprovided by the MIB.

DL resource allocation is performed in a unit of subframe and a group ofphysical resource blocks (PRBs). A transmission BW includes frequencyresource units referred to as resource blocks (RBs). Each RB includesN_(EPDCCH) sub-carriers, or resource elements (REs), such as 12 REs. Aunit of one RB over one subframe is referred to as a PRB. A UE can beallocated n_(s)=(n_(s0)+y·N_(EPDCCH)) mod D RBs for a total ofZ=O_(F)+└n_(s0)+y·N_(EPDCCH))/D┘ REs for the PDSCH transmission BW.

UL signals can include data signals conveying data information, controlsignals conveying UL control information (UCI), and UL RS. UL RSincludes DMRS and Sounding RS (SRS). A UE transmits DMRS only in a BW ofa respective PUSCH or PUCCH. An eNodeB can use a DMRS to demodulate datasignals or UCI signals. A UE transmits SRS to provide an eNodeB with anUL CSI. A UE transmits data information or UCI through a respectivephysical UL shared channel (PUSCH) or a Physical UL control channel(PUCCH). If a UE needs to transmit data information and UCI in a same ULsubframe, the UE may multiplex both in a PUSCH. UCI includes HybridAutomatic Repeat request acknowledgement (HARQ-ACK) information,indicating correct (ACK) or incorrect (NACK) detection for a data TB ina PDSCH or absence of a PDCCH detection (DTX), scheduling request (SR)indicating whether a UE has data in the UE's buffer, rank indicator(RI), and channel state information (CSI) enabling an eNodeB to performlink adaptation for PDSCH transmissions to a UE. HARQ-ACK information isalso transmitted by a UE in response to a detection of a PDCCH/EPDCCHindicating a release of semi-persistently scheduled PDSCH.

An UL subframe includes two slots. Each slot includes N_(symb) ^(UL)symbols for transmitting data information, UCI, DMRS, or SRS. Afrequency resource unit of an UL system BW is a RB. A UE is allocatedN_(RB) RBs for a total of N_(RB)·N_(SC) ^(RB) REs for a transmission BW.For a PUCCH, N_(RB)=1. A last subframe symbol can be used to multiplexSRS transmissions from one or more UEs. A number of subframe symbolsthat are available for data/UCI/DMRS transmission isN_(symb)=2·(N_(symb) ^(UL)−1)−N_(SRS), where N_(SRS)=1 if a lastsubframe symbol is used to transmit SRS and N_(SRS)=0 otherwise.

FIG. 5 illustrates a transmitter block diagram 500 for a PDSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the transmitter block diagram 500 illustrated in FIG. 5 isfor illustration only. One or more of the components illustrated in FIG.5 can be implemented in specialized circuitry configured to perform thenoted functions or one or more of the components can be implemented byone or more processors executing instructions to perform the notedfunctions. FIG. 5 does not limit the scope of this disclosure to anyparticular implementation of the transmitter block diagram 500.

As shown in FIG. 5, information bits 510 are encoded by encoder 520,such as a turbo encoder, and modulated by modulator 530, for exampleusing quadrature phase shift keying (QPSK) modulation. A serial toparallel (S/P) converter 540 generates M modulation symbols that aresubsequently provided to a mapper 550 to be mapped to REs selected by atransmission BW selection unit 555 for an assigned PDSCH transmissionBW, unit 560 applies an Inverse fast Fourier transform (IFFT), theoutput is then serialized by a parallel to serial (P/S) converter 570 tocreate a time domain signal, filtering is applied by filter 580, and asignal transmitted 590. Additional functionalities, such as datascrambling, cyclic prefix insertion, time windowing, interleaving, andothers are well known in the art and are not shown for brevity.

FIG. 6 illustrates a receiver block diagram 600 for a PDSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the diagram 600 illustrated in FIG. 6 is for illustrationonly. One or more of the components illustrated in FIG. 6 can beimplemented in specialized circuitry configured to perform the notedfunctions or one or more of the components can be implemented by one ormore processors executing instructions to perform the noted functions.FIG. 6 does not limit the scope of this disclosure to any particularimplementation of the diagram 600.

As shown in FIG. 6, a received signal 610 is filtered by filter 620, REs630 for an assigned reception BW are selected by BW selector 635, unit640 applies a fast Fourier transform (FFT), and an output is serializedby a parallel-to-serial converter 650. Subsequently, a demodulator 660coherently demodulates data symbols by applying a channel estimateobtained from a DMRS or a CRS (not shown), and a decoder 670, such as aturbo decoder, decodes the demodulated data to provide an estimate ofthe information data bits 680. Additional functionalities such astime-windowing, cyclic prefix removal, de-scrambling, channelestimation, and de-interleaving are not shown for brevity.

FIG. 7 illustrates a transmitter block diagram 700 for a PUSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the block diagram 700 illustrated in FIG. 7 is forillustration only. One or more of the components illustrated in FIG. 5can be implemented in specialized circuitry configured to perform thenoted functions or one or more of the components can be implemented byone or more processors executing instructions to perform the notedfunctions. FIG. 7 does not limit the scope of this disclosure to anyparticular implementation of the block diagram 700.

As shown in FIG. 7, information data bits 710 are encoded by encoder720, such as a turbo encoder, and modulated by modulator 730. A discreteFourier transform (DFT) unit 740 applies a DFT on the modulated databits, REs 750 corresponding to an assigned PUSCH transmission BW areselected by transmission BW selection unit 755, unit 760 applies an IFFTand, after a cyclic prefix insertion (not shown), filtering is appliedby filter 770 and a signal transmitted 780.

FIG. 8 illustrates a receiver block diagram 800 for a PUSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the block diagram 800 illustrated in FIG. 8 is forillustration only. One or more of the components illustrated in FIG. 8can be implemented in specialized circuitry configured to perform thenoted functions or one or more of the components can be implemented byone or more processors executing instructions to perform the notedfunctions. FIG. 8 does not limit the scope of this disclosure to anyparticular implementation of the block diagram 800.

As shown in FIG. 8, a received signal 810 is filtered by filter 820.Subsequently, after a cyclic prefix is removed (not shown), unit 830applies a FFT, REs 840 corresponding to an assigned PUSCH reception BWare selected by a reception BW selector 845, unit 850 applies an inverseDFT (IDFT), a demodulator 860 coherently demodulates data symbols byapplying a channel estimate obtained from a DMRS (not shown), a decoder870, such as a turbo decoder, decodes the demodulated data to provide anestimate of the information data bits 880.

FIG. 9 illustrates an example of beams 900 according to embodiments ofthe present disclosure. The embodiment of the beams 900 illustrated inFIG. 9 is for illustration only. One or more of the componentsillustrated in FIG. 9 can be implemented in specialized circuitryconfigured to perform the noted functions or one or more of thecomponents can be implemented by one or more processors executinginstructions to perform the noted functions. FIG. 9 does not limit thescope of this disclosure to any particular implementation of the beams900.

The 3GPP NR specification supports up to 32 CSI-RS antenna ports whichenable an eNB to be equipped with a large number of antenna elements(such as 64 or 128). In this case, a plurality of antenna elements ismapped onto one CSI-RS port. For mmWave bands, although the number ofantenna elements can be larger for a given form factor, the number ofCSI-RS ports—which can correspond to the number of digitally precodedports—tends to be limited due to hardware constraints (such as thefeasibility to install a large number of ADCs/DACs at mmWavefrequencies) as illustrated in FIG. 9. In this case, one CSI-RS port ismapped onto a large number of antenna elements which can be controlledby a bank of analog phase shifters 901. One CSI-RS port can thencorrespond to one sub-array which produces a narrow analog beam throughanalog beamforming 905. This analog beam can be configured to sweepacross a wider range of angles (920) by varying the phase shifter bankacross symbols or subframes. The number of sub-arrays (equal to thenumber of RF chains) is the same as the number of CSI-RS portsN_(CSI-PORT). A digital beamforming unit 910 performs a linearcombination across N_(CSI-PORT) analog beams to further increaseprecoding gain. While analog beams are wideband (hence notfrequency-selective), digital precoding can be varied across frequencysub-bands or resource blocks. Receiver operation can be conceivedanalogously.

Since the above system utilizes multiple analog beams for transmissionand reception (wherein one or a small number of analog beams areselected out of a large number, for instance, after a trainingduration—to be performed from time to time), the term “multi-beamoperation” is used to refer to the overall system aspect. This includes,for the purpose of illustration, indicating the assigned DL or ULtransmit (TX) beam (also termed “beam indication”), measuring at leastone reference signal for calculating and performing beam reporting (alsotermed “beam measurement” and “beam reporting”, respectively), andreceiving a DL or UL transmission via a selection of a correspondingreceive (RX) beam.

The above system is also applicable to higher frequency bands suchas >52.6 GHz (also termed the FR4). In this case, the system can employonly analog beams. Due to the O2 absorption loss around 60 GHz frequency(˜10 dB additional loss @ 100 m distance), larger number of and sharperanalog beams (hence larger number of radiators in the array) will beneeded to compensate for the additional path loss.

In the 3GPP NR specification, multi-beam operation is designed primarilyfor single transmit-receive point (TRP) and single antenna panel.Therefore, the specification supports beam indication for one TX beamwherein a TX beam is associated with a reference RS. For DL beamindication and measurement, the reference RS can be NZP (non-zero power)CSI-RS and/or SSB (synchronization signal block, which includes primarysynchronization signal, secondary synchronization signal, and PBCH).Here, DL beam indication is done via the transmission configurationindicator (TCI) field in DL-related DCI which includes an index to one(and only one) assigned reference RS. A set of hypotheses or theso-called TCI states is configured via higher-layer (RRC) signaling and,when applicable, a subset of those TCI states is selected/activated viaMAC CE for the TCI field code points. For UL beam indication andmeasurement, the reference RS can be NZP CSI-RS, SSB, and/or SRS. Here,UL beam indication is done via the SRS resource indicator (SRI) field inUL-related DCI which is linked to one (and only one) reference RS. Thislinkage is configured via higher-layer signaling using theSpatialRelationInfo RRC parameter. Essentially, only one TX beam isindicated to the UE.

In the 3GPP NR specification, beam management was designed to share thesame framework as CSI acquisition. This, however, compromises theperformance of beam management especially for FR2. This is because beammanagement operates mainly with analog beams (characteristic of FR2)which paradigmatically differ from CSI acquisition (designed with FR1 inmind). Consequently, the 3GPP NR specification beam management becomescumbersome and is unlikely able to keep up with more aggressive usecases which require large number of beams and fast beam switching (e.g.,higher frequency bands, high mobility, and/or larger number of narroweranalog beams). In addition, the 3GPP NR specification was designed toaccommodate a number of unknown or rudimentary capabilities (e.g., UEsnot capable of beam correspondence). To be flexible, it results in anumber of options. This becomes burdensome to L1 control signaling andtherefore a number of reconfigurations are performed via RRC signaling(higher-layer configuration). While this avoids L1 control overhead, iteither results in high latency (if reconfiguration is performedsparsely) or imposes high usage of PDSCH (since RRC signaling consumesPDSCH resources).

In one example, when beam correspondence is utilized, UL beam selectioncan be performed via measuring DL RS (CSI-RS and/or SSB) and CRIreporting accompanied with corresponding beam metrics (e.g., RSRP,SINR). That is, based on the CRI/RSRP or CRI/SINR reporting from the UE,the network (NW) can assume that the UE performs UL transmission onPUSCH with the UL TX beam associated with one of the latest CRI reports(especially the one with the highest RSRP or/SINR). Likewise, the UE canassume that the NW knows about this UE selection. Therefore, there is noneed for a separate UL beam indication (e.g., via the SRI field or theUL-TCI field in the respective UL grant).

In the 3GPP NR specification, when beam correspondence is not utilized,UL beam selection can be performed via the NW selecting the UL TX beamand indicating it to the UE via the UL grant (signaled via SRI field orUL-TCI field—essentially indicating the UL TCI state associated with theUL TX beam). This selection is enabled by measuring the SRS transmittedfrom the UE (configured by the NW).

In either case, when an event that results in the UE having to select an(alternate) UL TX beam different from what the NW expects, someadditional mechanisms are needed to ensure that (a) the UE has thealternate UL TX beam available when the UE detects such an event and thenext UL TX beam indication can only in a later time slot, and (b) the NWis aware of the UE decision. A few examples of such an event are asfollows.

In one example, such an event can happen due to the so-called MaximumPermissible Exposure (MPE) regulation, especially in North America, thatrestricts the UE transmission power in certain directions. That is, toprevent any excessive electromagnetic wave exposure on delicate softtissues (e.g., brain tissues), the UE is to avoid transmitting highenergy signal along some directions (e.g., toward the head).Unfortunately, such directions may correspond to the “best” UL TX beams(e.g., associated with the CRI of the highest reported RSRP/SINR, orassociated with the SRS resource yielding the best measured SINR at theNW). When the “best” UL TX beams are not used for UL transmission, someloss of UL throughput (especially coverage) will occur.

In another example, such an event can happen due to hardware (HW)limitation at a UE equipped with multiple antenna panels, and inresponse to the event, the UE needs to select/switch antenna panel forUL transmission.

In yet another example, such an event can happen due to potential beamfailure, and to avoid beam failure, the UE needs to select/switchantenna panel for UL transmission.

In yet another example, such an event can happen due to a sudden changein channel conditions (e.g., due to high speed, antenna/panel blockage,etc.) which may result in beam failure, and the UE needs toswitch/change TX beam in order to continue UL transmission withoutinterruptions/failures or having to wait for the next UL TX beamupdate/indication.

Therefore, there is a need for efficient designs for enabling“alternate” UL TX beam selection (without having to wait for the next ULTX beam indication) in order to avoid outage (or beam failure), loss inUL throughput, loss in UL coverage, and issues related to HW, that mayhappen due to the events mentioned above. In this disclosure, severalexample embodiments are proposed for such designs.

In the present disclosure, the term “activation” describes an operationwherein a UE receives and decodes a signal from the network (or gNB)that signifies a starting point in time. The starting point can be apresent or a future slot/subframe or symbol—the exact location eitherimplicitly or explicitly indicated, or otherwise fixed or higher-layerconfigured. Upon successfully decoding the signal, the UE respondsaccordingly. The term “deactivation” describes an operation wherein a UEreceives and decodes a signal from the network (or gNB) that signifies astopping point in time. The stopping point can be a present or a futureslot/subframe or symbol—the exact location either implicitly orexplicitly indicated, or otherwise fixed or higher-layer configured.Upon successfully decoding the signal, the UE responds accordingly.

Terminology such as TCI, TCI states, SpatialRelationInfo, target RS,reference RS, and other terms is used for illustrative purposes andtherefore not normative. Other terms that refer to the same functionscan also be used.

A “reference RS” corresponds to a set of characteristics of DL or UL TXbeam, such as direction, precoding/beamforming, number of ports, etc.For instance, as the UE receives a reference RS index/ID in a DLassignment represented by a TCI state, the UE applies the knowncharacteristics of the reference RS to the assigned DL transmission. Inan alternative, the reference RS included in a TCI state is referred toas a source RS (e.g., to distinguish an RS included in a TCI state froman RS configured for beam measurement/reporting). The reference RS canbe received and measured by the UE (in this case, the reference RS is adownlink signal such as NZP CSI-RS and/or SSB) with the result of themeasurement used for calculating a beam report (in the 3GPP NRspecification, at least one L1-RSRP accompanied by at least one CRI). Asthe NW/gNB receives the beam report, the NW can be better equipped withinformation to assign a particular DL TX beam to the UE. Optionally, thereference RS can be transmitted by the UE (in this case, the referenceRS is a downlink signal such as SRS). As the NW/gNB receives thereference RS, the NW/gNB can measure and calculate the neededinformation to assign a particular DL TX beam to the UE. This option isapplicable when DL-UL beam pair correspondence holds.

The reference RS can be dynamically triggered by the NW/gNB (e.g., viaDCI in case of aperiodic RS), preconfigured with a certain time-domainbehavior (such as periodicity and offset, in case of periodic RS), or acombination of such pre-configuration and activation/deactivation (incase of semi-persistent RS).

There are two types of frequency range (FR) defined in 3GPP NRspecifications. The sub-6 GHz range is called frequency range 1 (FR1)and millimeter wave range is called frequency range 2 (FR2). An exampleof the frequency range for FR1 and FR2 is shown below.

Frequency range designation Corresponding frequency range FR1 450MHz-600 MHz FR2 24250 MHz-52600 MHz

The following embodiment is an example of DL multi-beam operation thatutilizes DL beam indication after the network (NW) receives sometransmission from the UE. In the first example embodiment, aperiodicCSI-RS is transmitted by the NW and measured by the UE. Althoughaperiodic RS is used in these two examples, periodic or semi-persistentRS can also be used.

For mmWave (or FR2) or higher frequency bands (such as >52.6 GHz or FR4)where multi-beam operation is especially relevant,transmission-reception process includes the receiver to select a receive(RX) beam for a given TX beam. For UL multi-beam operation, the gNBselects an UL RX beam for every UL TX beam (which corresponds to areference RS). Therefore, when UL RS (such as SRS and/or DMRS) is usedas reference RS, the NW/gNB triggers or configures the UE to transmitthe UL RS (which is associated with a selection of UL TX beam). The gNB,upon receiving and measuring the UL RS, selects an UL RX beam. As aresult, a TX-RX beam pair is derived. The NW/gNB can perform thisoperation for all the configured reference RS s (either per reference RSor “beam sweeping”) and determine all the TX-RX beam pairs associatedwith all the reference RSs configured to the UE. On the other hand, whenDL RS (such as CSI-RS and/or SSB) is used as reference RS (pertinentwhen DL-UL beam correspondence or reciprocity holds), the NW/gNBtransmit the RS to the UE (for UL and by reciprocity, this correspondsto an UL RX beam). In response, the UE measures the reference RS (and inthe process selects an UL TX beam) and reports the beam metricassociated with the quality of the reference RS. In this case, the UEdetermines the TX-RX beam pair for every configured (DL) reference RS.Therefore, although this knowledge is unavailable to the NW/gNB, theUE—upon receiving a reference RS (hence UL RX beam) indication from theNW/gNB—can select the UL TX beam from the knowledge on all the TX-RXbeam pairs.

In the present disclosure, the term “Resource Indicator”, alsoabbreviated as REI, is used to refer to an indicator of RS resource usedfor signal/channel and/or interference measurement. This term is usedfor illustrative purposes and hence can be substituted with any otherterm that refers to the same function. Examples of REI include theaforementioned CSI-RS resource indicator (CRI) and SSB resourceindicator (SSB-RI). Any other RS can also be used for signal/channeland/or interference measurement such as DMRS.

In one example illustrated in FIG. 10, an UL multi-beam operation 1000is shown. The embodiment of the UL multi-beam operation 1000 illustratedin FIG. 10 is for illustration only. FIG. 10 does not limit the scope ofthis disclosure to any particular implementation of the UL multi-beamoperation 1000.

The UL multi-beam operation 1000 starts with starts with the gNB/NWsignaling to a UE an aperiodic CSI-RS (AP-CSI-RS) trigger or indication(step 1001). This trigger or indication can be included in a DCI (eitherUL-related or DL-related, either separately or jointly signaled with anaperiodic CSI request/trigger) and indicate transmission of AP-CSI-RS ina same (zero time offset) or later slot/sub-frame (>0 time offset). Uponreceiving the AP-CSI-RS transmitted by the gNB/NW (step 1002), the UEmeasures the AP-CSI-RS and, in turn, calculates and reports a “beammetric” (indicating quality of a particular TX beam hypothesis) (step1003). Examples of such beam reporting are CSI-RS resource indicator(CRI) or SSB resource indicator (SSB-RI) coupled with its associatedL1-RSRP/L1-RSRQ/L1-SINR/CQI. Upon receiving the beam report from the UE,the NW can use the beam report to select an UL TX beam for the UE andindicate the UL TX beam selection (step 1004) using the SRI field in theUL-related DCI (that carries the UL grant, such as DCI format 0_1 inNR). The SRI corresponds to a “target” SRS resource that is linked to areference RS (in this case, an AP-CSI-RS) via SpatialRelationInfoconfiguration. Upon successfully decoding the UL-related DCI with theSRI, the UE performs UL transmission (such as data transmission onPUSCH) with the UL TX beam associated with the SRI (step 1005).

In another example illustrated in FIG. 11, an UL multi-beam operation1100 is shown. The embodiment of the UL multi-beam operation 1100illustrated in FIG. 11 is for illustration only. FIG. 11 does not limitthe scope of this disclosure to any particular implementation of the ULmulti-beam operation 1100.

The UL multi-beam operation 1100 starts with the gNB/NW signaling to aUE an aperiodic SRS (AP-SRS) trigger or request (step 1101). Thistrigger can be included in a DCI (either UL-related or DL-related). Uponreceiving and decoding the AP-SRS trigger (step 1102), the UE transmitsAP-SRS to the gNB/NW (step 1103) so that the NW (or gNB) can measure theUL propagation channel and select an UL TX beam for the UE. The gNB/NWcan then indicate the UL TX beam selection (step 1104) using the SRIfield in the UL-related DCI (that carries the UL grant, such as DCIformat 0_1 in NR). The SRI corresponds to a “target” SRS resource thatis linked to a reference RS (in this case, an AP-SRS) viaSpatialRelationInfo configuration. Upon successfully decoding theUL-related DCI with the SRI, the UE performs UL transmission (such asdata transmission on PUSCH) with the UL TX beam associated with the SRI(step 1105).

In another example illustrated in FIG. 12, a DL multi-beam operation1200 is shown. The embodiment of the DL multi-beam operation 1200illustrated in FIG. 12 is for illustration only. FIG. 12 does not limitthe scope of this disclosure to any particular implementation of the DLmulti-beam operation 1200.

In the example illustrated in FIG. 12, where a UE is configured formeasuring/receiving aperiodic CSI-RS (AP-CSI-RS) and reporting aperiodicCSI (AP CSI), a DL multi-beam operation 1200 starts with the gNB/NWsignaling to a UE an aperiodic CSI-RS (AP-CSI-RS) trigger or indication(step 1201). This trigger or indication can be included in a DCI (eitherUL-related or DL-related, either separately or jointly signaled with anaperiodic CSI request/trigger) and indicate transmission of AP-CSI-RS ina same (zero time offset) or later slot/sub-frame (>0 time offset). Uponreceiving the AP-CSI-RS transmitted by the gNB/NW (step 1202), the UEmeasures the AP-CSI-RS and, in turn, calculates and reports a “beammetric” (included in the CSI, indicating quality of a particular TX beamhypothesis) (step 1203). Examples of such beam reporting (supported inthe 3GPP NR specification) are CSI-RS resource indicator (CRI) or SSBresource indicator (SSB-RI) coupled with its associated L1-RSRP and/orL1-SINR. Upon receiving the beam report from the UE, the NW/gNB can usethe beam report to select a DL TX beam for the UE and indicate the DL TXbeam selection (step 1204) using the TCI field in the DL-related DCI(that carries the DL assignment, such as DCI format 1_1 in NR). The TCIstate corresponds to a reference RS (in this case, an AP-CSI-RS)defined/configured via the TCI state definition (higher-layer/RRCconfigured, from which a subset is activated via MAC CE for theDCI-based selection). Upon successfully decoding the DL-related DCI withthe TCI field, the UE performs DL reception (such as data transmissionon PDSCH) with the DL TX beam associated with the TCI field (step 1205).In this example embodiment, only one DL TX beam is indicated to the UE.

In the above two example embodiments illustrated in FIGS. 10 and 11,only one UL TX beam is indicated to the UE. The SRI used in embodimentsillustrated in FIGS. 10 and 11 can also be replaced with UL-TCI whereinan UL-TCI field can be introduced in the pertinent UL-related DCI(s),either in place of or in addition to the SRI field in the 3GPP NRspecification.

The aperiodic CSI-RS (along with the associated aperiodic reporting) inthe embodiment illustrated in FIG. 10 and the aperiodic SRS in theembodiment illustrated in FIG. 1100 can be substituted with that ofanother time-domain behavior such as semi-persistent (SP) or periodic(P).

In any of the embodiments or sub-embodiments or examples below, aflowchart is used for illustrative purposes. The present disclosurecovers any possible variation of the flowchart as long as at least someof the components are included. Such components include the UL TX beamindication indicating multiple UL TX beams and the event-dependent UL TXbeam switch from the indicated multiple UL TX beams.

In the rest of the disclosure, the term “beam”, can be associated with aspatial transmission/reception of a resource signal (RS) from a “port”,“antenna port”, or “virtual antenna/port”. Likewise, the term “transmit(TX) beam”, can be associated with a spatial transmission of a resourcesignal (RS) or a channel from a “port”, “antenna port”, or “virtualantenna/port”; and the term “receive (RX) beam”, can be associated witha spatial reception of a resource signal (RS) or a channel from a“port”, “antenna port”, or “virtual antenna/port”. The spatialtransmission/reception of a beam can be in a three-dimension (3D) space.In a beam-formed wireless system, the transmission and reception ofwireless signal can be via multiple TX and multiple RX beams.

The present disclosure includes the following components for efficientdesigns for enabling “alternate” UL TX beam selection (without having towait for the next UL TX beam indication) when an event (such as the onesmentioned above) is detected at the UE.

Component 1—UE Procedures for Event-Based UL TX Beam Switch

In one embodiment (I), a UE is configured to receive UL TX beamindication indicating multiple (N) UL TX beams. The UE is furtherconfigured to transmit UL transmission (such as data transmission onPUSCH) with a UL TX beam selected from the multiple UL TX beams. In oneexample, for a UE with single antenna panel (SP), N>1 UL TX beams areindicated for MPE mitigation. In one example, for a UE with multipleantenna panels (MP), N>1 UL TX beams are indicated for fast panel switchand/or MPE mitigation.

FIG. 13 illustrates a flow diagram of a UE configured to receive an ULTX beam indication indicating two beams (B₁, B₂) 1300. The embodiment ofthe UE configured to receive an UL TX beam indication indicating twobeams (B₁, B₂) 1300 illustrated in FIG. 13 is for illustration only.FIG. 13 does not limit the scope of this disclosure to any particularimplementation of the UE configured to receive an UL TX beam indicationindicating two beams (B₁, B₂) 1300.

In one sub-embodiment (I.1), as shown in FIG. 13, a UE is configured toreceive an UL TX beam indication indicating two beams (B₁, B₂), where B₁is a first UL TX beam and B₂ is a second UL TX beam. The UE is furtherconfigured to transmit UL transmission (such as data transmission onPUSCH) with a UX TX beam B, where the UL TX beam B is one of the twobeams (B₁, B₂).

The UE also performs an event detection procedure to determine whetheran event of interest occurs while using the UL TX beam B for ULtransmission, where a few examples of the event of interest aredescribed above. If the event is not detected (i.e., declared negative),the UE continues to transmit UL transmission with the UL TX beam B. Ifthe event is detected (i.e., declared positive), the UE switches to analternate UL TX beam B′ for UL transmission, where the alternate UL TXB′≠B and is one of the two beams (B₁, B₂). At least one of the followingexamples is used to determine UL TX beams for UL transmission in futuretime slots.

-   -   In one example, the UE continues to transmit UL transmission        with the alternate UL TX beam B′ until it receives an update of        the UL TX beam indication in a future time slot.    -   In one example, the UE can switch back to the UL TX beam B for        UL transmission, for example, when the event of interest is        detected (i.e., declared positive) while using the alternate UL        TX beam B′ for UL transmission or when the event of interest is        not detected (i.e., declared negative) if the UL TX beam B is        used again for UL transmission.

In one example, the UL TX beam B is fixed, for example, to B₁. In oneexample, the UL TX beam B is configured, for example, B=B_(i) and theindex i ∈{1,2} is configured via RRC and/or MAC CE and/or DCI. In oneexample, the UE is free to select the UL TX beam B from (B₁, B₂).

The information about the event occurrence can be acquired at the NW/gNBimplicitly or explicitly. For implicit information, the UE may notreport any message about the event occurrence, but the NW/gNB by someimplementation can acquire the information, for example, based on thereceived UL transmission (since the UL TX beam switches from B to B′when the event occurs). For explicit information, the UE can explicitlyreport a pre-notification message to indicate to the NW/gNB that theevent occurred. The NW/gNB can transmit the next UL TX beam indication(in a future time slot) depending on the acquired implicit or explicitinformation about the event occurrence.

In an alternative explicit method, which doesn't require anypre-notification message, the UE can include/report the information ofthe selected beam (either B or B′), or UL TCI state, e.g., using a 1-bitindication. In one example, this information can be included/reportedtogether with the granted PUSCH transmission (either UCI only ormultiplexed with the UL data). In one example, this information can beincluded/reported concurrently with the UL control on PUCCH within thesame slot (either as a standalone information or multiplexed with otherUCI or HARQ-ACK). In one example, this information can beincluded/reported together with the PRACH transmission. The UE can beconfigured with at least one UL reporting resource forincluding/reporting the information of the selected beam, where the atleast one UL reporting resource corresponds to either PUCCH resource(s),PUSCH resource(s), or a combination between PUCCH and PUSCH resources,or PRACH resource(s). This resource configuration can be performed viahigher-layer (RRC) signaling. Alternatively, the NW/gNB can signal a setof reserved resources dynamically via L1 or L2 DL control (PDCCH or MACCE). In one example, the information of the selected beam can beincluded/multiplexed in the beginning portion (e.g., one of theallocated PRBs and/or the first OFDM symbol of the UL reportingresource) of the PUCCH or PUSCH transmission.

At least one of the following examples is used/configured regarding forthe inclusion of the information of the selected UL TX beam selection onPUCCH and/or PUSCH and/or PRACH.

-   -   In one example I.1.1, the UE is configured via a higher layer        (RRC) configuration for the reporting/inclusion of the        UE-selected UL TX beam or TCI state. The configuration can        include a dedicated parameter for this purpose. Alternatively,        the configuration can be jointly via an existing higher layer        RRC parameter. This configuration can be subject to UE        capability, i.e., only when the UE reports that it is capable of        such inclusion/reporting, the NW/gNB can configure the UE for        the inclusion/reporting of the UE selected UE TX beam.    -   In one example I.1.2, the UE is dynamically signaled via MAC CE        and/or DCI for the reporting/inclusion of the UE-selected UL TX        beam or TCI state. The dynamic signaling can include a dedicated        parameter or field for this purpose. Alternatively, this can be        jointly via an existing parameter or field. This signaling can        be subject to UE capability, i.e., only when the UE reports that        it is capable of such inclusion/reporting, the NW/gNB can signal        the UE for the inclusion/reporting of the UE selected UE TX        beam.    -   In one example I.1.3, the UE is configured via a combination of        higher layer (RRC) configuration and MAC CE (or DCI) signaling        to configure the reporting/inclusion of the UE-selected UL TX        beam or TCI state. This configuration can be subject to UE        capability, i.e., only when the UE reports that it is capable of        such inclusion/reporting, the NW/gNB can configure/signal the UE        for the inclusion/reporting of the UE selected UE TX beam.    -   In one example I.1.4, the configuration/signaling regarding the        reporting/inclusion of the UE-selected UL TX beam or TCI state        (as described in example I.1.1 through I.1.3) is restricted only        to the case when the UE is equipped with multiple antenna        panels. That is, for a UE with single antenna panel, such        inclusion/reporting is not allowed (can't be configured).    -   In one example I.1.5, the configuration/signaling regarding the        reporting/inclusion of the UE-selected UL TX beam or TCI state        (as described in example I.1.1 through I.1.3) is restricted only        to an event of interest (such as MPE issue).

The event detection by the UE can be based on at least one DLmeasurement RS such as CSI-RS or SSB, which can be configuredspecifically for the purpose of event detection, or it can be from theDL measurement RS(s) configured for beam measurement, beam reporting andbeam indication.

In this sub-embodiment, the UE starts transmitting UL transmission withthe UL TX beam B, then performs the event detection, and if the event isdeclared positive, the UE switches to the alternate UL TX beam B′ for ULtransmission.

FIG. 14 illustrates a flow diagram of a UE configured to receive an ULTX beam indication indicating two beams (B₁, B₂) 1400. The embodiment ofthe UE configured to receive an UL TX beam indication indicating twobeams (B₁, B₂) 1400 illustrated in FIG. 14 is for illustration only.FIG. 14 does not limit the scope of this disclosure to any particularimplementation of the UE configured to receive an UL TX beam indicationindicating two beams (B₁, B₂) 1400.

In one sub-embodiment (I.2), as shown in FIG. 14, a UE is configured toreceive an UL TX beam indication indicating two beams (B₁, B₂), where B₁is a first UL TX beam and B₂ is a second UL TX beam. The UE firstperforms the event detection, and if the event is declared negative, theUE transmits UL transmission (such as data transmission on PUSCH) with aUL TX beam B, else the UE transmits UL transmission with the alternateUL TX beam B′, where B≠B′ and B and B′ are selected from the two beams(B₁, B₂). The UE repeats these steps until the UE receives the next ULTX beam indication in a future time slot.

The rest of the details of this sub-embodiment are the same assub-embodiment I.1. In particular, as described in sub-embodiment I.1,the information about the event occurrence can be acquired at the NW/gNBimplicitly or explicitly. For implicit information, the UE may notreport any message about the event occurrence, but the NW/gNB by someimplementation can acquire the information, for example, based on thereceived UL transmission (since the UL TX beam switches from B to B′when the event occurs). For explicit information, the UE can explicitlyreport a pre-notification message to indicate to the NW/gNB that theevent occurred. The NW/gNB can transmit the next UL TX beam indication(in a future time slot) depending on the acquired implicit or explicitinformation about the event occurrence.

In an alternative explicit method, which doesn't require anypre-notification message, the UE can include/report the information ofthe selected beam (either B or B′), or UL TCI state, e.g., using a 1-bitindication. In one example, this information can be included/reportedtogether with the granted PUSCH transmission (either UCI only ormultiplexed with the UL data). In one example, this information can beincluded/reported concurrently with the UL control on PUCCH within thesame slot (either as a standalone information or multiplexed with otherUCI or HARQ-ACK). In one example, this information can beincluded/reported together with the PRACH transmission. The UE can beconfigured with at least one UL reporting resource forincluding/reporting the information of the selected beam, where the atleast one UL reporting resource corresponds to either PUCCH resource(s),PUSCH resource(s), or a combination between PUCCH and PUSCH resources,or PRACH resource(s). This resource configuration can be performed viahigher-layer (RRC) signaling. Alternatively, the NW/gNB can signal a setof reserved resources dynamically via L1 or L2 DL control (PDCCH or MACCE). In one example, the information of the selected beam can beincluded/multiplexed in the beginning portion (e.g., one of theallocated PRBs and/or the first OFDM symbol of the UL reportingresource) of the PUCCH or PUSCH transmission. At least one of theexamples I.1.1 through I.1.5 can be used/configured regarding for theinclusion of the information of the selected UL TX beam selection onPUCCH and/or PUSCH and/or PRACH.

In one example, the UE uses one of sub-embodiments I.1 and I.2 for ULtransmission depending on the event of interest. For instance, if theevent of interest is MPE, then the UE uses sub-embodiment I.2, and ifthe event of interest is related to HW limitation or beam failure, thenthe UE uses sub-embodiment I.1. In another example, one ofsub-embodiments I.1 and I.2 is configured to the UE, for example, viaRRC and/or MAC CE and/or DCI. In another example, one of sub-embodimentsI.1 and I.2 is fixed (used) for UL transmission. In another example, theUE reports one of or both of sub-embodiments I.1 and I.2 in itscapability signaling, and the NW/gNB configures one of them subject tothe reported UE capability.

FIG. 15 illustrates a flow diagram of a UE configured to receive an ULTX beam indication indicating N beams (B₁, B₂, . . . , B_(N)) 1500. Theembodiment of the UE configured to receive an UL TX beam indicationindicating N beams (B₁, B₂, . . . , B_(N)) 1500 illustrated in FIG. 15is for illustration only. FIG. 15 does not limit the scope of thisdisclosure to any particular implementation of the UE configured toreceive an UL TX beam indication indicating N beams (B₁, B₂, . . . ,B_(N)) 1500.

In one sub-embodiment (I.3), as shown in FIG. 15, a UE is configured toreceive an UL TX beam indication indicating N beams (B₁, B₂, . . . ,B_(N)), where B₁ is a first UL TX beam, B₂ is a second UL TX beam, . . .B_(N) is a N-th UL TX beam. The UE is further configured to transmit ULtransmission (such as data transmission on PUSCH) with a UX TX beam B,where the UL TX beam B is selected from the N beams (B₁, B₂, . . . ,B_(N)).

The UE also performs an event detection procedure to determine whetheran event of interest occurs while using the UL TX beam B for ULtransmission, where a few examples of the event of interest is describedabove. If the event is not detected (i.e., declared negative), the UEcontinues to transmit UL transmission with the UL TX beam B. If theevent is detected (i.e., declared positive), the UE switches to analternate UL TX beam B′ for UL transmission, where the alternate UL TXB′≠B and is selected from the N beams (B₁, B₂, . . . , B_(N)). At leastone of the following examples is used to determine UL TX beams for ULtransmission in future time slots.

-   -   In one example, the UE continues to transmit UL transmission        with the alternate UL TX beam B′ until it receives an update of        the UL TX beam indication in a future time slot.    -   In one example, the UE can switch to a second alternate UL TX        beam B″ for UL transmission, for example, when the event of        interest is detected (i.e., declared positive) while using any        one of B and B′ for UL transmission, where B″≠B′, B″≠B, and B″        is selected from the N beams (B₁, B₂, . . . , B_(N)).    -   In one example, the UE can switch back to the UL TX beam B for        UL transmission, for example, when the event of interest is        detected (i.e., declared positive) while using any one of        alternate UL TX beam B′, B″, . . . for UL transmission or when        the event of interest is not detected (i.e., declared negative)        if the UL TX beam B is used again for UL transmission.

In one example, the UL TX beam B is fixed, for example, to B₁. In oneexample, the UL TX beam B is configured, for example, B=B₁ and the indexi ∈{1, . . . , N} is configured via RRC and/or MAC CE and/or DCI. In oneexample, the UE is free to select the UL TX beam B from (B₁, . . . ,B_(N)). In one example, the N UL TX beams are ordered (sorted) indecreasing order of priority such that B_(i) is higher priority thanB_(j) if i<j. When the event is declared positive, the UE selects thehighest priority UL TX beam for UL transmission from the set ofcandidate UL TX beams (that corresponds to the set (B₁, B₂, . . . ,B_(N)) minus the UL TX beam when the event is declared). The priorityorder of the N beams can be fixed (e.g., based on their indices), or itis configured via RRC and/or MAC CE and/or DCI.

The value of N is either fixed (e.g., N=2, N=number of antenna panels atthe UE), or configured via RRC and/or MAC CE and/or DCI. Alternatively,the UE reports at least one N value that it supports. Such a reportingcan be via UE capability signaling. Alternatively, the UE reports one Nvalue which corresponds to a number of active antenna panels out of atotal number of antenna panels at the UE. Note that the number of activeantenna panels can be less that the total number of antenna panels atthe UE.

As described in sub-embodiment I.1, the information about the eventoccurrence can be acquired at the NW/gNB implicitly or explicitly. Forimplicit information, the UE may not report any message about the eventoccurrence, but the NW/gNB by some implementation can acquire theinformation, for example, based on the received UL transmission (sincethe UL TX beam switches from B to B′ when the event occurs). Forexplicit information, the UE can explicitly report a pre-notificationmessage to indicate to the NW/gNB that the event occurred. The NW/gNBcan transmit the next UL TX beam indication (in a future time slot)depending on the acquired implicit or explicit information about theevent occurrence.

In an alternative explicit method, which doesn't require anypre-notification message, the UE can include/report the information ofthe selected beam (either B or B′), or UL TCI state, e.g., using a ┌log₂N┐ bit indication. In one example, this information can beincluded/reported together with the granted PUSCH transmission (eitherUCI only or multiplexed with the UL data). In one example, thisinformation can be included/reported concurrently with the UL control onPUCCH within the same slot (either as a standalone information ormultiplexed with other UCI or HARQ-ACK). In one example, thisinformation can be included/reported together with the PRACHtransmission. The UE can be configured with at least one UL reportingresource for including/reporting the information of the selected beam,where the at least one UL reporting resource corresponds to either PUCCHresource(s), PUSCH resource(s), or a combination between PUCCH and PUSCHresources, or PRACH resource(s). This resource configuration can beperformed via higher-layer (RRC) signaling. Alternatively, the NW/gNBcan signal a set of reserved resources dynamically via L1 or L2 DLcontrol (PDCCH or MAC CE). In one example, the information of theselected beam can be included/multiplexed in the beginning portion(e.g., one of the allocated PRBs and/or the first OFDM symbol of the ULreporting resource) of the PUCCH or PUSCH transmission. At least one ofthe examples I.1.1 through I.1.5 can be used/configured regarding forthe inclusion of the information of the selected UL TX beam selection onPUCCH and/or PUSCH and/or PRACH.

The event detection by the UE can be based on at least one DLmeasurement RS such as CSI-RS or SSB, which can be configuredspecifically for the purpose of event detection, or it can be from theDL measurement RS(s) configured for beam measurement, beam reporting andbeam indication.

In this sub-embodiment, the UE starts transmitting UL transmission withthe UL TX beam B, then performs the event detection, and if the event isdeclared positive, the UE switches to the alternate UL TX beam B′ for ULtransmission.

FIG. 16 illustrates a flow diagram of a UE configured to receive an ULTX beam indication indicating N beams (B₁, B₂, . . . , B_(N)) 1600. Theembodiment of the UE configured to receive an UL TX beam indicationindicating N beams (B₁, B₂, . . . , B_(N)) 1600 illustrated in FIG. 16is for illustration only. FIG. 16 does not limit the scope of thisdisclosure to any particular implementation of the UE configured toreceive an UL TX beam indication indicating N beams (B₁, B₂, . . . ,B_(N)) 1600.

In one sub-embodiment (1.4), as shown in FIG. 16, a UE is configured toreceive UL TX beam indication indicating N beams (B₁, B₂, . . . ,B_(N)), where B₁ is a first UL TX beam, B₂ is a second UL TX beam, . . .B_(N) is a N-th UL TX beam. The UE first performs the event detection,and if the event is declared negative, the UE transmits UL transmission(such as data transmission on PUSCH) with a UL TX beam B, else the UEtransmits UL transmission with the alternate UL TX beam B′, where B≠B′and B and B′ are selected from the N beams (B₁, B₂, . . . , B_(N)). TheUE repeats these steps until the UE receives the next UL TX beamindication in a future time slot.

The rest of the details of this sub-embodiment are the same assub-embodiment I.3. In particular, as described in sub-embodiment I.1,the information about the event occurrence can be acquired at the NW/gNBimplicitly or explicitly. For implicit information, the UE may notreport any message about the event occurrence, but the NW/gNB by someimplementation can acquire the information, for example, based on thereceived UL transmission (since the UL TX beam switches from B to B′when the event occurs). For explicit information, the UE can explicitlyreport a pre-notification message to indicate to the NW/gNB that theevent occurred. The NW/gNB can transmit the next UL TX beam indication(in a future time slot) depending on the acquired implicit or explicitinformation about the event occurrence.

In an alternative explicit method, which doesn't require anypre-notification message, the UE can include/report the information ofthe selected beam (either B or B′), or UL TCI state, e.g., using a ┌log₂N┐ bit indication. In one example, this information can beincluded/reported together with the granted PUSCH transmission (eitherUCI only or multiplexed with the UL data). In one example, thisinformation can be included/reported concurrently with the UL control onPUCCH within the same slot (either as a standalone information ormultiplexed with other UCI or HARQ-ACK). In one example, thisinformation can be included/reported together with the PRACHtransmission. The UE can be configured with at least one UL reportingresource for including/reporting the information of the selected beam,where the at least one UL reporting resource corresponds to either PUCCHresource(s), PUSCH resource(s), or a combination between PUCCH and PUSCHresources, or PRACH resource(s). This resource configuration can beperformed via higher-layer (RRC) signaling. Alternatively, the NW/gNBcan signal a set of reserved resources dynamically via L1 or L2 DLcontrol (PDCCH or MAC CE). In one example, the information of theselected beam can be included/multiplexed in the beginning portion(e.g., one of the allocated PRBs and/or the first OFDM symbol of the ULreporting resource) of the PUCCH or PUSCH transmission. At least one ofthe examples I.1.1 through I.1.5 can be used/configured regarding forthe inclusion of the information of the selected UL TX beam selection onPUCCH and/or PUSCH and/or PRACH.

In one example, the UE uses one of sub-embodiments I.3 and I.4 for ULtransmission depending on the event of interest. For instance, if theevent of interest is MPE, then the UE uses sub-embodiment I.4, and ifthe event of interest is related to HW limitation or beam failure, thenthe UE uses sub-embodiment I.3. In another example, one ofsub-embodiments I.3 and I.4 is configured to the UE, for example, viaRRC and/or MAC CE and/or DCI. In another example, one of sub-embodimentsI.3 and I.4 is fixed (used) for UL transmission. In another example, theUE reports one of or both of sub-embodiments I.3 and I.4 in itscapability signaling, and the NW/gNB configures one of them subject tothe reported UE capability.

FIG. 17 illustrates an algorithmic description of the UL TX beamselection for UL transmission 1700. The embodiment of the algorithmicdescription of the UL TX beam selection for UL transmission 1700illustrated in FIG. 17 is for illustration only. FIG. 17 does not limitthe scope of this disclosure to any particular implementation of thealgorithmic description of the UL TX beam selection for UL transmission1700.

In one sub-embodiment (I.5), as shown in FIG. 17, an algorithmicdescription of the UL TX beam selection for UL transmission as describedin embodiments I.3 through I.4 can include the following steps.

-   -   Let S₁=(B₂, . . . , B_(N)), S_(N)=(B₁, . . . , B_(N-1)), and        S_(k)=(B₁, . . . , B_(k−1), B_(k+1), . . . , B_(N)) for k ∈{2, .        . . , N−1}. Note S_(k) corresponds to N−1 UL TX beams obtained        after removing the UL TX beams B_(k).    -   Step 0: The UE transmits UL transmission with a UL TX beam B        selected from the N beams (B₁, B₂, . . . , B_(N)). Let B=B_(k)        where k E {1, 2, . . . , N}. Initialize T′=S_(k) and B′=B.    -   Step 1: Check if the event of interest is detected (i.e.,        declared positive). If yes, proceed to Step 2; else the UE        continues UL transmission with the current UL TX beam and        proceeds to Step 3.    -   Step 2: The UE selects an alternative UL TX beam B′ from the N−1        beams in T′ for UL transmission. Let k′ be the index of the        alternate UL TX beam B, i.e., B′=B_(k), and set T′=S_(k),    -   Step 3: If next UL TX beam indication is received, proceed to        Step 0; else proceed to Step 1.

In one sub-embodiment (I.6), when the UE can transmit (or is capable oftransmitting) UL transmission with two UL TX beams simultaneously, theUE transmits UL transmission using both UL TX beams (B₁, B₂) as long asthe event of interest is not declared with any of the two beams (B₁,B₂). When the event of interest is declared (positive) with a beam Bfrom the two beams (B₁, B₂), the UE transmits UL transmission using theother (alternate) UL TX beam (≠B) from the two beams (B₁, B₂). The UErepeats these steps until it receives the next UL TX beam indication ina future time slot. Upon the reception of the next UL TX beamindication, the UE updates the two beams (B₁, B₂), and proceeds with ULtransmission using the two new UL TX beams as described above. If the UEreceives N>2 beams via the UL TX beam indication, then the UE selectstwo beams from the N beams before proceeding with UL transmissiondescribed above, where the selection of the two beams can be fixed orconfigured via RRC and/or MAC CE and/or DCI.

Component 2—Alternate UL TX Beam(s) Measurement, Reporting, andIndication

In one embodiment (II), a UE is configured to receive DL RS(s) (ortransmit UL RS(s)) for beam measurement at the UE (or at the gNB). TheUE can further be configured with beam reporting. The beam measurementand beam reporting are configured in order to facilitate UL TX beamindication indicating multiple UL TX beams as described in embodiment Iand sub-embodiments I.1 through I.6. Note that this configuration ofbeam measurement and reporting is separate (different) from the explicitindication/reporting of the UL beam or TCI state selection (B or B′) forUL transmission, as described earlier in the disclosure. That is, the ULbeam selection is not a part of beam reporting—rather it is a companionto the granted UL transmission. The beam reporting (from the UE) is tofacilitate beam indication (from the NW/gNB) indicating the beams (B₁, .. . . , B_(N)), and the UL beam selection (from the UE) is to let gNB/NWknow about the UL TX beam selected for the UL transmission from theindicated beams (B₁, . . . , B_(N)).

In one sub-embodiment (II.1), a UE is configured to perform beammeasurement and reporting according to at least one of the followingexamples.

In one example II.1.1, the UE is configured (by the NW/gNB) to measure(receive) P₁ DL measurement RS resources (such as CSI-RS or SSB), whereP₁≥1. This configuration can be performed via higher-layer (RRC)signaling. Optionally, the NW/gNB can signal/update the (sub)set of DLmeasurement RS resources dynamically via L1 or L2 DL control (PDCCH orMAC CE). These resources are used by the UE to perform beam measurementalong different beams or spatial directions (represented by thebeamforming/precoding operation performed at the NW/gNB transparent tothe UE). The UE is further configured (by the NW/gNB) to report Q₁resource indicators (I) or Q₁ pairs of (1,1)=(resource indicator, beammetric), where Q₁≤P₁. The beam metric can represent link qualityassociated with data (PDSCH) and/or dedicated control (PDCCH). Examplesof beam metric include L1-RSRP, L1-SINR, CQI, or hypothetical BLER, orany other beam metric. The resource indicator indicates a DL measurementRS resource index from the P₁ DL measurement RS resources. Examples ofresource indicator include CRI (when DL measurement RS is CSI-RS) andSSB-RI (when DL measurement RS is SSB). The time-domain behavior of thisbeam reporting can be configured as aperiodic (AP), semi-persistent(SP), or periodic (P). The NW/gNB receives Q₁ resource indicators (I) orQ₁ pairs of (I, J)=(resource indicator, beam metric), and uses them toconfigure the UL TX beam indication indicating N UL TX beams (for theUE). In one example, N=N₁. In one example, N₁ is configured via RRCand/or MAC CE and/or DCI.

In one example II.1.2, the UE is configured (by the NW/gNB) to measure(receive) P₁ DL measurement RS resources (such as CSI-RS or SSB), whereP₁≥1. The details of this beam measurement are as described above inExample II.1.1. The UE is further configured (by the NW/gNB) to reportQ₁ resource indicator sets or Q₁ pairs of (resource indicator sets, beammetric), where Q₁≤P₁, and each resource indicator set includes N₁resource indicators (I₁, . . . I_(N)) with I_(i) being the i-th resourceindicator in the set. The details about beam metric, resource indicator,and time-domain behavior of beam reporting are as described above inExample II.1.1. The NW/gNB receives Q₁ resource indicator sets or Q₁pairs of (resource indicator sets, beam metric), and uses them toconfigure the UL TX beam indication indicating N UL TX beams (for theUE). In one example, N=N₁. In one example, N₁ is configured via RRCand/or MAC CE and/or DCI.

In one example II.1.3, the UE is configured (by the NW/gNB) to measure(receive) P₁ DL measurement RS resources (such as CSI-RS or SSB), whereP₁>1. The details of this beam measurement are as described above inExample II.1.1. The UE is further configured (by the NW/gNB) to report(R₁, . . . R_(N)) or (R₁, . . . R_(N), beam metric), where for each i,R₁ is a set of resource indicators for the i-th beam in N UL TX beams(indicated by the NW/gNB). The details about beam metric, resourceindicator, and time-domain behavior of beam reporting are as describedabove in Example II.1.1. The NW/gNB receives (R₁, . . . R_(N)) or (R₁, .. . R_(N), beam metric), and uses it to configure the UL TX beamindication indicating N UL TX beams (for the UE).

In one example II.1.4, the UE is configured (by the NW/gNB) to measure(receive) P₁ DL measurement RS resources (such as CSI-RS or SSB), whereP₁>1. The details of this beam measurement are as described above inExample II.1.1. The is further configured with a set X comprisingcandidate resource indicators (I₁, . . . I_(N)) for UL TX beamindication, where I_(i) corresponds to the DL measurement RS for thei-th beam in N UL TX beams (indicated by the NW/gNB). The UE is furtherconfigured (by the NW/gNB) to report Q₁ resource indicators (I₁, . . .I_(N)) or Q₁ pairs of (resource indicators, beam metric)=(I₁, . . .I_(N), beam metric), where Q₁≥1, and the reported resource indicators(I₁, . . . I_(N)) are from the configured set X. The details about beammetric, resource indicator, and time-domain behavior of beam reportingare as described above in Example II.1.1. The NW/gNB receives Q₁resource indicators (I₁, . . . I_(N)) or Q₁ pairs of (resourceindicators, beam metric)=(I₁, . . . I_(N), beam metric), and uses themto configure the UL TX beam indication indicating N UL TX beams (for theUE).

In one example II.1.5, the UE is configured (by the NW/gNB) to measure(receive) N sets of DL measurement RS resources (such as CSI-RS or SSB),where the i-th set of DL measurement RS resources is for the i-th beamin N UL TX beams (indicated by the NW/gNB). The details of this beammeasurement are as described above in Example II.1.1. In one example, Nsets are associated with N antenna panels at the UE. In one example, Nsets are associated with N range of spatial (or beam) directions at theUE. The UE is further configured (by the NW/gNB) to report Q₁ resourceindicator sets or Q₁ pairs of (resource indicator sets, beam metric),where Q₁≥1, and each resource indicator set includes N resourceindicators (I₁, . . . I_(N)) with I_(i) being the i-th resourceindicator in the set that is selected from the i-th set of DLmeasurement RS resources. The details about beam metric, resourceindicator, and time-domain behavior of beam reporting are as describedabove in Example II.1.1. The NW/gNB receives Q₁ resource indicator setsor Q₁ pairs of (resource indicator sets, beam metric), and uses them toconfigure the UL TX beam indication indicating N UL TX beams (for theUE).

In one example II.1.6, the UE is configured (by the NW/gNB) to transmitP₂ UL measurement RS resources (such as SRS), where P₂≥1. Thisconfiguration can be performed via higher-layer (RRC) signaling.Optionally, the NW/gNB can signal/update the (sub)set of UL measurementRS resources dynamically via L1 or L2 DL control (PDCCH or MAC CE).These SRS resources can be used by the NW/gNB to perform beammeasurement along different beams or spatial directions (represented bythe beamforming/precoding operation performed at the UE transparent tothe NW/gNB). The UE can optionally be configured to report Q₂ candidateUL TX beam indications, e.g., via UL-TCI(s), where UL-TCI represents anUL TCI state as configured in the UL TCI state definition (viahigher-layer signaling) wherein a TCI state is linked/associated to ameasurement RS that can be used to represent an UL “direction” (i.e., ULTX beam). In this sub-embodiment, the UL TCI state is linked to an SRSresource index (SRI) which represents a configured SRS resource sinceSRS is used to measure the link quality of the UL channel(s).

The NW/gNB receives (measures) P₂ UL measurement RS resources (and,optionally, Q₂ candidate UL TX beam indications), and uses them toconfigure the UL TX beam indication indicating N UL TX beams (for theUE).

In one example II.1.7, the UE is configured (by the NW/gNB) to transmitN sets of UL measurement RS resources (such as SRS), where the i-th setof UL measurement RS resources is for the i-th beam in N UL TX beams(indicated by the NW/gNB). The details of the UL measurement RS resourceare as described above in Example II.1.6. In one example, N sets areassociated with N antenna panels at the UE. In one example, N sets areassociated with N range of spatial (or beam) directions at the UE. TheUE can optionally be configured to report Q₂ candidate UL TX beamindications, e.g., via UL-TCI(s), where UL-TCI represents an UL TCIstate as configured in the UL TCI state definition (via higher-layersignaling) wherein a TCI state is linked/associated to a measurement RSthat can be used to represent an UL “direction” (i.e., UL TX beam). Inthis sub-embodiment, the UL TCI state is linked N SRS resource indices(SRIs), one from each of the N sets of UL measurement RS resources.

The NW/gNB receives (measures) N sets of UL measurement RS resources(and, optionally, Q₂ candidate UL TX beam indications), and uses them toconfigure the UL TX beam indication indicating N UL TX beams (for theUE).

In one example II.1.8, the UE is configured (by the NW/gNB) to transmitP₂ UL measurement RS resources (cf. Example II.1.6) or N sets of ULmeasurement RS resources (cf. Example II.1.7). The details of the ULmeasurement RS resource are as described above in Example II.1.6. In oneexample, N sets are associated with N antenna panels at the UE. In oneexample, N sets are associated with N range of spatial (or beam)directions at the UE. The UE is further configured to report multiplesets of candidate UL TX beam indications, e.g., via UL-TCI(s), wheremultiple sets can be associated with multiple antenna panels at the UE,or multiple range of spatial (or beam) directions at the UE.

The NW/gNB receives (measures) UL measurement RS resources and multiplesets of candidate UL TX beam indications, and selects a beam from eachset, or selects a subset of the multiple sets, and then selects a beamfrom each subset. The NW/gNB then uses them to configure the UL TX beamindication indicating N UL TX beams (for the UE).

In one example II.1.9, the UE is configured (by the NW/gNB) to measure(receive) P₁ DL measurement RS resources (such as CSI-RS or SSB), whereP₁≥1. The details of this beam measurement are as described above inExample II.1.1. The UE is further configured (by the NW/gNB) to reportQ₁ resource indicators (I) or Q₁ pairs of (I, J)=(resource indicator,beam metric), where Q₁≤P₁.

The UE is also configured (by the NW/gNB) to transmit P₂ UL measurementRS resources (such as SRS), where P₂≥1. The details of the ULmeasurement RS resource are as described above in Example II.1.6. The UEcan optionally be configured to report Q₂ candidate UL TX beamindications, e.g., via UL-TCI(s).

The NW/gNB receives (measures) UL measurement RS resources, receives Q₁resource indicators (I) or Q₁ pairs of (I, J)=(resource indicator, beammetric), and optionally receives Q₂ candidate UL TX beam indications.The NW/gNB then uses the received information to configure the UL TXbeam indication indicating N UL TX beams (for the UE).

In one example, when N=2, a first of N UL TX beams (B₁) is selectedbased on Q₁ resource indicators (I) or Q₁ pairs of (I, J)=(resourceindicator, beam metric), and a second of N UL TX beams (B₂) is selectedbased on Q₂ candidate UL TX beam indications.

In one example, when N>2, a first of N UL TX beams (B₁) is selectedbased on Q₁ resource indicators (I) or Q₁ pairs of (I, J)=(resourceindicator, beam metric), and remaining N−1 of N UL TX beams (B₂, . . . ,B_(N-2)) are selected based on Q₂ candidate UL TX beam indications.

In one sub-embodiment (II.2), a UE is configured to receive the UL TXbeam indication indicating N UL TX beams (as described above) via A-TCIwhere A=DL or UL or J (joint). The UE can be configured via RRCsignaling with a set of TCI states, where each TCI state corresponds toa A-TCI indicating N UL TX beams. The UE can be configured to receive aMAC CE command that selects a TCI state from the set of TCI states.Alternatively, the UE can be configured to receive a MAC CE command thatselects a subset of TCI states from the set of TCI states, and the UEcan be furthered configured to receive a code point in DCI thatindicates a TCI state from the subset of TCI states. At least one of thefollowing examples is used for the UL TX beam indication.

In one example II.2.1, the UL TX beam indication indicating N UL TXbeams is via UL-TCI(s). In one example, a joint (single) UL-TCI is usedto indicate N UL TX beams (i.e., UL-TCI includes a TCI state ID and IDsof N DL or UL measurement RS resources each with one port, or UL-TCIincludes a TCI state ID and an ID of DL or UL measurement RS resourcewith N ports). In one example, N (separate) UL-TCIs are used to indicateN UL TX beams, one for each UL TX beam (i.e., each UL-TCI includes a TCIstate ID and an ID of a DL or UL measurement RS resource with one port).For UL operation (e.g., as in Rel. 15/16 NR), a UE can also be indicatedseparately with SRI(s) (in addition to UL-TCI(s)). Alternatively, SRI(s)is (are) indicated (jointly) via UL-TCI(s).

In one example II.2.2, one of the N UL TX beams is the same as DL TXbeam, hence is indicated via DL-TCI (e.g., when beam correspondenceholds), and the remaining N−1 UL TX beams are indicated via UL-TCI(s).In one example, a joint (single) UL-TCI is used to indicate N−1 UL TXbeams. In one example, N−1 (separate) UL-TCIs are used to indicate N−1UL TX beams, one for each UL TX beam. For UL operation (e.g., as in Rel.15/16 NR), a UE can also be indicated separately with SRI(s) (inaddition to UL-TCI(s)). Alternatively, SRI(s) is (are) indicated(jointly) via UL-TCI(s). Additionally, the information whether the beamindicated via DL-TCI is the primary beam (e.g., B₁), or one of theremaining beams indicated via UL-DCI(s) is the primary beam is provided(e.g., via a flag or parameter). This information can be provided viaRRC and/or MAC CE and/or DCI.

In one example II.2.3, the beam indication indicating N beams (B₁, . . ., B_(N)) is via UL-TCI(s) or DL-DCI(s) or J-TCI(s), where this beamindication is common for both DL reception and UL transmission (e.g.,assuming beam correspondence holds). In one example, a joint (single)A-TCI is used to indicate N beams. In one example, N (separate) A-TCIsare used to indicate N beams, one for each beam. Here, A is either UL orDL or J.

In one example, a beam B_(DL) from (B₁, . . . , B_(N)) is used for DLreception, and beams (B₁, . . . , B_(N)) are used for UL transmission asdescribed in this disclosure. In one example, B_(DL)=B₁ where i is fixed(e.g., to 1). In one example, B_(DL) is configured via RRC and/or MAC CEand/or DCI.

In one example II.2.4, the beam indication about one of the N beams (B₁,. . . , B_(N)) is via TCI1, where TCI1 is either UL-TCI1 or DL-TCI1 orJ-DCI1. The beam indication about the remaining N−1 beams, say N beams(B₂, . . . , B_(N)) is via TCI2, where TCI2 is either UL-TCI2 or DL-TCI2or J-TCI2.

In one example II.2.5, one of N beams is indicated via a TCI1 (that isindicated via DCI), and the remaining N−1 beams are indicated via TCI2(that is indicated via MAC CE or RRC or a combination of MACE CE andRRC).

In one example II.2.6, the beam indication indicating N beams isaccording to one of Example II.2.1 through II.2.5 except the following.One of N beams (B₁, . . . , B_(N)), say B₁, is always indicated. Theremaining N−1 beams, say N beams (B₂, . . . , B_(N)) may or may not beindicated. The information whether remaining N−1 beams are indicated canbe configured via RRC and/or MACE CE and/or DCI. When DCI is used, atwo-stage DCI can be used, where the first stage DCI includes theinformation whether remaining N−1 beams are indicated. Depending on thisinformation in the first stage DCI, the second stage DCI may or may notbe provided to the UE.

In one sub-embodiment (II.3), the beam measurement, beam reporting, andbeam indication is subject to a restriction/condition.

Such restrictions can only be for some (not all) events such as MPEmitigation. Alternatively, such events can be applied regardless of theevent. Also, the restriction can be applied in a non-transparent manner.For example, the UE can be configured to apply such restrictions and/orthe UE can report that it is capable to applying such restrictions. Atleast one of the following examples is used for such restrictions.

In one example II.3.1, the restriction is based on a number of antennapanels (Z) at the UE. For instance, N=1 when Z=1, and N>1 when Z>1.

In one example II.3.2, the restriction is based on a minimum separationacross N beams in angular/spatial domain. In one example of therestriction in angular domain, any two out of N beams are such thattheir beam pointing directions or beam patterns are (almost)non-overlapping (e.g., for MPE mitigation). In one example of therestriction in spatial domain, the N beams are orthogonal.

In one example II.3.2, the restriction is based on a combination ofExample II.3.1 and Example II.3.2.

Component 3—Miscellaneous Embodiments

In one sub-embodiment (III.1), a UE is configured to receive UL TX beamindication indicating multiple (N) UL TX beams. The UE is furtherconfigured to transmit UL transmission (such as data transmission onPUSCH) with a UL TX beam B selected from the N UL TX beams. The UEselects the UL TX beams B for UL transmission and the gNB/NW receives ULtransmission according to at least one of the following examples.

In one example III.1.1, the UE is free to select any of the N UL TXbeams for UL transmission. The NW/gNB performs blind decoding for theselected UL TX beam B while receiving the UL transmission.Alternatively, the UE reports a message with the selected UL TX beam tothe NW/gNB, which uses it to receive UL transmission.

In one example 111.1.2, The UE selects the UL TX beams B for ULtransmission according to a priority order (fixed or configuredpriority), i.e., the UE selects the highest priority UL TX beam (e.g.,1^(st) beam B₁) for UL transmission. If an event of interest (asdescribed in this disclosure) is not declared, the NW/gNB receives theUL transmission with a UL RX beam associated with the highest priorityUL TX beam. Else, the UE switches to (selects) an alternate UL TX beamfrom the UE transmission. For example, the UE selects the second highestpriority UL TX beam (e.g., 2^(nd) beam B₂) for UL transmission. When thesecond highest priority UL TX beam is selected, the NW/gNB performsblind decoding for the selected UL TX beam B while receiving the ULtransmission. For example, the NW/gNB decodes using the second highestpriority UL TX beam if the decoding fails using the highest priority ULTX beam. Alternatively, the UE reports a message with the selected UL TXbeam to the NW/gNB, which uses it to receive UL transmission.

In one sub-embodiment (III.2), when the UE is configured with ULmeasurement RS (SRS) resources for UL TX beam indication as described inthis disclosure, the configuration includes a higher layer parameterSRSResourceSet with ‘usage’ set to ‘multiplepanels’ or ‘multiple UL TXbeams’ or ‘BeamManagement’, and the N UL TX beam indication is based onN SRS resources in SRSResourceSet. Alternatively, the configurationincludes N higher layer parameters SRSResourceSet, each with ‘usage’ setto ‘multiplepanels’ or ‘multiple UL TX beams’ or ‘BeamManagement’, andthe N UL TX beam indication is based on N SRS resources, one from eachof N SRSResourceSet.

In one sub-embodiment (III.3), when the UE is configured with DLmeasurement RS (e.g., CSI-RS) resources for UL TX beam indication asdescribed in this disclosure, the configuration includes a higher layerparameter CSI-RSResourceSet, and the N UL TX beam indication is based onN CSI-RS resources in CSI-RSResourceSet. Alternatively, theconfiguration includes N higher layer parameters CSI-RSResourceSet, andthe N UL TX beam indication is based on N CSI-RS resources, one fromeach of N CSI-RSResourceSet.

In one sub-embodiment (III.4), a UE reports (either dynamically via L1control, or via MAC CE, or via its capability signaling) informationregarding its capability to receive N>1 UL TX beams. Alternatively, theUE reports (either dynamically via L1 control, or via MAC CE, or via itscapability signaling) information regarding its capability to receiveN>1 UL TX beams and an information whether the UE supports one antennapanel (SP) or multiple panels (MP) for UL transmission. Alternatively,the UE reports (either dynamically via L1 control, or via MAC CE, or viaits capability signaling) information regarding its capability whetherthe UE supports one antenna panel (SP) or multiple panels (MP) for ULtransmission. The UL TX beam indication is subject to the reported UEcapability.

In one sub-embodiment (III.5), a UE is configured to select a UL TX beamfrom the beams (B₁, . . . , B_(N)), indicated via the beam indication,for UL transmission, wherein the beam selection procedure is accordingto at least one of the following examples.

-   -   In one example, the beam selection is up to UE implementation,        i.e., the UE is free to select any beam for UL transmission.    -   In one example, the beam selection is based on a priority order        if an event of interest is not detected (e.g., MPE requirement        is met); otherwise, the beam selection is up to UE        implementation to select another panel, wherein the details of        the priority order is as described in Example III.1.2.    -   In one example, the beam selection is based on a priority order        if an event of interest is not detected (e.g., MPE requirement        is met); otherwise, the beam selection is using a beam with the        highest priority such that an event of interest is not detected        (e.g., MPE requirement is met) with the selected beam.    -   In one example, the beam selection is based on a priority order        such that an event of interest is not detected (e.g., MPE        requirement is met) with the selected beam.

In one example, N equals a number of antenna panels at the UE, and hencebeam selection is equivalent to panel selection in this case. In oneexample, when the UE is equipped with multiple antenna panels, the beamselection at the UE can be extended to include both beam and panelselection.

In one sub-embodiment (III.6), a UE is configured to report/indicate aninformation about the selected beam (and/or panel) to the NW/gNB, asdescribed in embodiment III.4 and elsewhere in this disclosure, whereinthe beam selection reporting/indication procedure is according to atleast one of the following examples.

-   -   In one example, there is no beam (and/or panel) indication,        i.e., the NW/gNB performs blind decoding for the selected UL TX        beam B while receiving the UL transmission.    -   In one example, the UE indicates an information about the        selected beam (and/or panel), e.g., beam ID or panel ID or an ID        associated with beam or panel, to the NW/gNB that is used for        upcoming UL transmission. The physical channel for this        indication can be PUCCH or PUSCH or PRACH or a combination of at        least two of PUCCH, PUSCH, and PRACH. When PUSCH is used for        this indication, then a MAC CE can be used for this indication.        When the MAC CE is absent (not provided), there is no        change/update in the beam (and/or panel). Alternatively, the        indication can be multiplexed with either UCI only or both UCI        and data. When PUCCH is used for this indication, a field in        PUCCH can be used for this indication. This field can be        optionally included when a beam (and/or panel) changes.    -   In one example, the UE indicates an information about the        selected beam (and/or panel), e.g., beam ID or panel ID or an ID        associated with beam or panel, to the NW/gNB that is used for        upcoming UL transmission only when there is a beam (and/or        panel) change. The physical channel this indication can be PUCCH        or PUSCH or PRACH or a combination of at least two of PUCCH,        PUSCH, and PRACH. When PUSCH is used for this indication, then a        MAC CE can be used for this indication. When the MAC CE is        absent (not provided), there is no change/update in the beam        (and/or panel). Alternatively, the indication can be multiplexed        with either UCI only or both UCI and data. When PUCCH is used        for this indication, a field in PUCCH can be used for this        indication. This field can be optionally included when a beam        (and/or panel) changes.

In one sub-embodiment (III.7), when the UE is configured with multiplecomponent carriers (CCs), the physical DL and/or UL channels describedin this disclosure to indicate beam (and/or panel) can be within thesame CC, or different CCs. This information (same of different CCs) canbe fixed (not configured), or can be configured to the UE.

Any of the above variation embodiments can be utilized independently orin combination with at least one other variation embodiment.

FIG. 18 illustrates a flow chart of a method 1800 for operating a userequipment (UE), as may be performed by a UE such as UE 116, according toembodiments of the present disclosure. The embodiment of the method 1800illustrated in FIG. 18 is for illustration only. FIG. 18 does not limitthe scope of this disclosure to any particular implementation.

As illustrated in FIG. 18, the method 1800 begins at step 1802. In step1802, the UE (e.g., 111-116 as illustrated in FIG. 1) receivesconfiguration information including information on a beam indicationindicating N uplink (UL) transmit beams, where N>1.

In step 1804, the UE receives the beam indication.

In step 1806, the UE determines whether an event is detected.

In step 1808, the UE selects a beam from the N UL transmit beams basedon whether the event is detected or not.

In step 1810, the UE transmits an UL transmission using the selectedbeam, wherein the beam refers to a spatial property used to receive ortransmit a source reference signal (RS).

In one embodiment, the UE, in response to the event not being detected,selects a first beam from the N UL transmit beams as the beam, and inresponse to the event being detected, selects a second beam from the NUL transmit beams as the beam.

In one embodiment, the event detection is based on whether a maximumpermissible exposure (MPE) limit is met or not.

In one embodiment, the UE is equipped with at least first and secondantenna panels, and to determine whether the event is detected, the UEdetermines whether to switch from the first antenna panel to the secondantenna panel.

In one embodiment, the beam is selected based on a priority order amongthe N UL transmit beams.

In one embodiment, the UE receives configuration information includinginformation about measurement RS resources and information about a beamreporting, measures the measurement RS resources and calculates the beamreporting based on the measured measurement RS resources, and transmitsthe beam reporting, where the measurement RS resources comprise channelstate information reference signals (CSI-RSs) or synchronization signalblocks (SSBs) or both CSI-RSs and SSBs, the beam reporting includes atleast one resource indicator and a beam metric associated with the atleast one resource indicator, and the beam indication is based on thebeam reporting.

In one embodiment, the beam indication is via a transmissionconfiguration indicator (TCI) state including at least one source RS.

In one embodiment, the beam indication is via N transmissionconfiguration indicator (TCI) states, one TCI state for each of the N ULtransmit beams, and each TCI state includes at least one source RS.

In one embodiment, the beam indication is via first and secondtransmission configuration indicator (TCI) states, TCI1 and TCI2,respectively, each of the first and second TCI states including at leastone source RS, and the UE uses the TCI1 to determine one of the N ULtransmit beams, and uses the TCI2 to determine remaining N−1 of the N ULtransmit beams.

FIG. 19 illustrates a flow chart of another method 1900, as may beperformed by a base station (BS) such as BS 102, according toembodiments of the present disclosure. The embodiment of the method 1900illustrated in FIG. 19 is for illustration only. FIG. 19 does not limitthe scope of this disclosure to any particular implementation.

As illustrated in FIG. 19, the method 1900 begins at step 1902. In step1902, the BS (e.g., 101-103 as illustrated in FIG. 1), receivesconfiguration information including information on a beam indicationindicating N uplink (UL) transmit beams, where N>1.

In step 1904, the BS generates the beam indication.

In step 1906, the BS transmits the configuration information.

In step 1908, the BS transmits the beam indication.

In step 1910, the BS receives an UL transmission transmitted using abeam from the N UL transmit beams, wherein the beam is selected based onwhether an event is detected, and wherein the beam refers to a spatialproperty used to receive or transmit a source reference signal (RS).

In one embodiment, if the event is not detected, the beam is a firstbeam from the N UL transmit beams, and if the event is detected, thebeam is a second beam from the N UL transmit beams.

In one embodiment, the event detection is based on whether a maximumpermissible exposure (MPE) limit is met or not.

In one embodiment, the beam is selected based on a priority order amongthe N UL transmit beams.

In one embodiment, the BS transmits configuration information includinginformation about measurement RS resources and information about a beamreporting, transmits the measurement RS resources, and receives the beamreporting, wherein the measurement RS resources comprise channel stateinformation reference signals (CSI-RSs) or synchronization signal blocks(SSBs) or both CSI-RSs and SSBs, the beam reporting includes at leastone resource indicator and a beam metric associated with the at leastone resource indicator, and the beam indication is based on the beamreporting.

In one embodiment, the beam indication is via a transmissionconfiguration indicator (TCI) state including at least one source RS.

In one embodiment, the beam indication is via N transmissionconfiguration indicator (TCI) states, one TCI state for each of the N ULtransmit beams, and each TCI state includes at least one source RS.

In one embodiment, the beam indication is via first and secondtransmission configuration indicator (TCI) states, TCI1 and TCI2,respectively, each of the first and second TCI states including at leastone source RS, the TCI1 indicates one of the N UL transmit beams, andthe TCI2 indicates remaining N−1 of the N UL transmit beams.

The above flowcharts illustrate example methods that can be implementedin accordance with the principles of the present disclosure and variouschanges could be made to the methods illustrated in the flowchartsherein. For example, while shown as a series of steps, various steps ineach figure could overlap, occur in parallel, occur in a differentorder, or occur multiple times. In another example, steps may be omittedor replaced by other steps.

Although the present disclosure has been described with an exemplaryembodiment, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims. None of the description in this application should be read asimplying that any particular element, step, or function is an essentialelement that must be included in the claims scope. The scope of patentedsubject matter is defined by the claims.

What is claimed is:
 1. A user equipment (UE) comprising: a transceiverconfigured to: receive configuration information including informationon a beam indication indicating N uplink (UL) transmit beams, where N>1,and receive the beam indication; and a processor operably coupled to thetransceiver, the processor configured to: determine whether an event isdetected, and select a beam from the N UL transmit beams based onwhether the event is detected or not, and wherein the transceiver isfurther configured to transmit an UL transmission using the selectedbeam, and wherein the beam refers to a spatial property used to receiveor transmit a source reference signal (RS).
 2. The UE of claim 1,wherein the processor is further configured to: in response to the eventnot being detected, select a first beam from the N UL transmit beams asthe beam, and in response to the event being detected, select a secondbeam from the N UL transmit beams as the beam.
 3. The UE of claim 1,wherein the event detection is based on whether a maximum permissibleexposure (MPE) limit is met or not.
 4. The UE of claim 1, wherein: theUE is equipped with at least first and second antenna panels, and theprocessor is further configured to determine that the event is detectedbased on a determination to switch from the first antenna panel to thesecond antenna panel.
 5. The UE of claim 1, wherein the beam is selectedbased on a priority order among the N UL transmit beams.
 6. The UE ofclaim 1, wherein: the transceiver is configured to receive configurationinformation including information about measurement RS resources andinformation about a beam reporting, the processor is configured tomeasure the measurement RS resources and calculate the beam reportingbased on the measured measurement RS resources, the transceiver isfurther configured to transmit the beam reporting, the measurement RSresources comprise channel state information reference signals (CSI-RSs)or synchronization signal blocks (SSBs) or both CSI-RSs and SSBs, thebeam reporting includes at least one resource indicator and a beammetric associated with the at least one resource indicator, and the beamindication is based on the beam reporting.
 7. The UE of claim 1, whereinthe beam indication is via a transmission configuration indicator (TCI)state including at least one source RS.
 8. The UE of claim 1, whereinthe beam indication is via N transmission configuration indicator (TCI)states, one TCI state for each of the N UL transmit beams, and each TCIstate includes at least one source RS.
 9. The UE of claim 1, wherein:the beam indication is via first and second transmission configurationindicator (TCI) states, TCI1 and TCI2, respectively, each of the firstand second TCI states including at least one source RS, and theprocessor is configured to: use the TCI1 to determine one of the N ULtransmit beams, and use the TCI2 to determine remaining N−1 of the N ULtransmit beams.
 10. A base station (BS) comprising: a processorconfigured to: generate configuration information including informationon a beam indication indicating N uplink (UL) transmit beams, where N>1,and generate the beam indication; and a transceiver operably coupled tothe processor, the transceiver configured to: transmit the configurationinformation, transmit the beam indication, and receive an ULtransmission transmitted using a beam from the N UL transmit beams,wherein the beam is selected based on whether an event is detected, andwherein the beam refers to a spatial property used to receive ortransmit a source reference signal (RS).
 11. The BS of claim 10,wherein: if the event is not detected, the beam is a first beam from theN UL transmit beams, and if the event is detected, the beam is a secondbeam from the N UL transmit beams.
 12. The BS of claim 10, wherein theevent detection is based on whether a maximum permissible exposure (MPE)limit is met or not.
 13. The BS of claim 10, wherein the beam isselected based on a priority order among the N UL transmit beams. 14.The BS of claim 10, wherein: the transceiver is configured to: transmitconfiguration information including information about measurement RSresources and information about a beam reporting, transmit themeasurement RS resources, and receive the beam reporting, themeasurement RS resources comprises channel state information referencesignal (CSI-RSs) or synchronization signal blocks (SSBs) or both CSI-RSsand SSBs, the beam reporting includes at least one resource indicatorand a beam metric associated with the at least one resource indicator,and the beam indication is based on the beam reporting.
 15. The BS ofclaim 10, wherein the beam indication is via a transmissionconfiguration indicator (TCI) state including at least one source RS.16. The BS of claim 10, wherein the beam indication is via Ntransmission configuration indicator (TCI) states, one TCI state foreach of the N UL transmit beams, and each TCI state includes at leastone source RS.
 17. The BS of claim 10, wherein: the beam indication isvia first and second transmission configuration indicator (TCI) states,TCI1 and TCI2, respectively, each of the first and second TCI statesincluding at least one source RS, the TCI1 indicates one of the N ULtransmit beams, and the TCI2 indicates remaining N−1 of the N ULtransmit beams.
 18. A method for operating a user equipment (UE), themethod comprising: receiving configuration information includinginformation on a beam indication indicating N uplink (UL) transmitbeams, where N>1; receiving the beam indication; determining whether anevent is detected; selecting a beam from the N UL transmit beams basedon whether the event is detected or not; and transmitting an ULtransmission using the selected beam, wherein the beam refers to aspatial property used to receive or transmit a source reference signal(RS).
 19. The method of claim 18, further comprising: in response to theevent not being detected, selecting the beam to be a first beam from theN UL transmit beams, and in response to the event being detected,selecting the beam to be a second beam from the N UL transmit beams. 20.The method of claim 18, wherein the beam indication is via atransmission configuration indicator (TCI) state including at least onesource RS.